How can i start learn playing positional chess?

After looking at some of your games, I will offer the usual advice.  You're losing games for the following reasons:

Not following opening principles.

Hanging material.

Missing simple tactics.

Trying to learn how to play "positionally" isn't going to help you, when you arent even understanding the basics.

Opening Principles:

1. Control the center squares – d4-e4-d5-e5

2. Develop your minor pieces toward the center – piece activity is the key

3. Castle

4. Connect your rooks

Tactics...tactics...tactics...

Pre Move Checklist:

1. Make sure all your pieces are safe. 

2. Look for forcing move: Checks, captures, threats. You want to look at ALL forcing moves (even the bad ones) this will force you look at, and see the entire board. 

3. If there are no forcing moves, you then want to remove any of your opponent’s pieces from your side of the board. 

4. If your opponent doesn’t have any of his pieces on your side of the board, then you want to improve the position of your least active piece. 

5. After each move by your opponent, ask yourself: "What is my opponent trying to do?"

Perhaps of interest to look at the table of contents in the book sample here:

http://www.gambitbooks.com/pdfs/A_Complete_Chess_Course.pdf

"... In order to maximize the benefits of [theory and practice], these two should be approached in a balanced manner. ... Play as many slow games (60 5 or preferably slower) as possible, ... The other side of improvement is theory. ... This can be reading books, taking lessons, watching videos, doing problems on software, etc. ..." - NM Dan Heisman (2002)
https://web.archive.org/web/20140627084053/http://www.chesscafe.com/text/heisman19.pdf
"... If it’s instruction, you look for an author that addresses players at your level (buying something that’s too advanced won’t help you at all). This means that a classic book that is revered by many people might not be useful for you. ..." - IM Jeremy Silman (2015)
https://www.chess.com/article/view/the-best-chess-books-ever
Here are some reading possibilities that I often mention:
Simple Attacking Plans by Fred Wilson (2012)https://web.archive.org/web/20140708090402/http://www.chesscafe.com/text/review874.pdf
http://dev.jeremysilman.com/shop/pc/Simple-Attacking-Plans-77p3731.htm
Logical Chess: Move by Move by Irving Chernev (1957)
https://web.archive.org/web/20140708104437/http://www.chesscafe.com/text/logichess.pdf
The Most Instructive Games of Chess Ever Played by Irving Chernev (1965)
https://chessbookreviews.wordpress.com/tag/most-instructive-games-of-chess-ever-played/
Winning Chess by Irving Chernev and Fred Reinfeld (1948)
https://web.archive.org/web/20140708093415/http://www.chesscafe.com/text/review919.pdf
Back to Basics: Tactics by Dan Heisman (2007)
https://web.archive.org/web/20140708233537/http://www.chesscafe.com/text/review585.pdf
https://www.chess.com/article/view/book-review-back-to-basics-tactics
Discovering Chess Openings by GM John Emms (2006)
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
Openings for Amateurs by Pete Tamburro (2014)
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
https://chessbookreviews.wordpress.com/tag/openings-for-amateurs/
https://www.mongoosepress.com/catalog/excerpts/openings_amateurs.pdf
Chess Endgames for Kids by Karsten Müller (2015)
https://chessbookreviews.wordpress.com/tag/chess-endgames-for-kids/
http://www.gambitbooks.com/pdfs/Chess_Endgames_for_Kids.pdf
A Guide to Chess Improvement by Dan Heisman (2010)
https://web.archive.org/web/20140708105628/http://www.chesscafe.com/text/review781.pdf
Studying Chess Made Easy by Andrew Soltis (2009)
https://web.archive.org/web/20140708090448/http://www.chesscafe.com/text/review750.pdf
Seirawan stuff:
http://seagaard.dk/review/eng/bo_beginner/ev_winning_chess.asp?KATID=BO&ID=BO-Beginner
http://www.nystar.com/tamarkin/review1.htm
https://web.archive.org/web/20140627132508/http://www.chesscafe.com/text/hansen173.pdf
https://www.chess.com/article/view/book-review-winning-chess-endings
https://web.archive.org/web/20140708092617/http://www.chesscafe.com/text/review560.pdf

https://www.chess.com/article/view/study-plan-directory

The basics of positional play are just simple logical observations like rooks on open flies, knights on outposts, centralization is good, safe king is good, that sort of thing.

Trying to jiu jitsu that into a win is fairly abstract / advanced, and requires among other things tactical proficiency.

Start with the basics + tactics, much later you can try to win games like Karpov  
(and remember that even Karpov would launch a big attack on your king if it would win)

Possibly helpful (at some point):
https://www.chess.com/article/view/test-your-positional-chess
https://www.chess.com/article/view/do-you-really-understand-positional-chess
50 Essential Chess Lessons by Steve Giddins
https://web.archive.org/web/20140708100833/http://www.chesscafe.com/text/review534.pdf
http://www.gambitbooks.com/pdfs/50_Essential_Chess_Lessons.pdf
Simple Chess by Michael Stean
https://web.archive.org/web/20140708104258/http://www.chesscafe.com/text/review400.pdf
Amateur's Mind by Jeremy Silman
https://web.archive.org/web/20140708094419/http://www.chesscafe.com/text/ammind.pdf
Chess for Hawks
https://www.newinchess.com/media/wysiwyg/product_pdf/9041.pdf
Chess Strategy: Move by Move by Adam Hunt
https://web.archive.org/web/20140708093249/http://www.chesscafe.com/text/review890.pdf
The Power of Pawns by GM Jörg Hickl (2016)
https://chessbookreviews.wordpress.com/tag/the-power-of-pawns/
https://www.newinchess.com/media/wysiwyg/product_pdf/9034.pdf

There seems to be some sentiment that one might be able to usefully try to read about some of this sort of thing without necessaily having an immediate aspiration to win games like Karpov:

http://www.gambitbooks.com/pdfs/A_Complete_Chess_Course.pdf
https://web.archive.org/web/20140708090402/http://www.chesscafe.com/text/review874.pdf
http://dev.jeremysilman.com/shop/pc/Simple-Attacking-Plans-77p3731.htm
https://web.archive.org/web/20140708104437/http://www.chesscafe.com/text/logichess.pdf
https://chessbookreviews.wordpress.com/tag/most-instructive-games-of-chess-ever-played/
http://seagaard.dk/review/eng/bo_beginner/ev_winning_chess.asp?KATID=BO&ID=BO-Beginner
http://www.nystar.com/tamarkin/review1.htm

Yeah, reading and learning about positional play is good. That's what I mean when I say go ahead and learn the basics.

I guess my point is... the OP says he wants to "play positionally" but... that doesn't really mean anything. To play well means you play with all the elements mixed together. Sure a game may be heavy in positional themes, like something we might imagine from Karpov, but to actually take that advantage and carry it to a win will almost certainly require strong tactics and endgame play too.

Tactics is the enemy of positional play!

Master the tactics first. (without proper tactics, all good plan will fail, eg, king side attck, ) 

Once you become an advanced player , 1600+, positional play become more important than tactics!!

When AKartikey12 referred to wanting to "learn to play positionally", my assumption was that the idea was to learn to incorporate some positional themes into the elements mixed together in games (without necessarily hoping to be able to right away correctly play "a game heavy in positional themes").

What if tactical mastery only comes gradually? Must positional thinking be put entirely on hold until one has earned the tactical diploma? And, anyway, who is it who makes decisions on the awarding of tactical diplomas?

Must something be ignored until it is more important than tactics?

http://www.gambitbooks.com/pdfs/A_Complete_Chess_Course.pdf

Thankyou everyone! I think i must first improve at basics,get stronger and then try to play with all the elements of chess mixed together

I will try positional chess when I'm 90years old. I been trying regular chess since 1952 . . .but I just paid for my diamond membership . . .

DENVER

Well, following opening principles is in fact positional play. I think a simple approach regarding positional play is be alert to both position and tactics. Thus always look for tactics and if you can't find any look for posibilities to put your pieces on better places thus improving your position.

In addition to that I would say: Some people seem to think that you shouldn't play positional until you are very good, but that doesn't make sense. You are just doing it at a simpler level compared with a master player. Basic opening principles like development and taking control of the center are positional ideas. Moving a knight away from the edge on to a better place is a positional idea. Other positional ideas are: Putting rooks behind pawns., open lines and files for your rooks. Anything that has to do with the position. Thus looking for improvement of your position goes hand in hand with looking for tactics and being alert to hanging pieces.

Playing positionally simply means doing what the position requires you to do... You can learn that by reading books, playing games, watching lectures etc in order to improve your chess in general.

If you mean playing positionally instead tactically ... I believe at our level such division doesn't really exist. 

possibly study queens gambit AKartikay , as that leads generally to positional games but not always as it can get tactical too , but give that a month of study esp master games , and i think that might help