At your level, tactics, basic endgames and basic opening principles will help a lot.
Should I Buy Chess.com premium and which books should I consider to improve myself?
Possibly helpful:
Simple Attacking Plans by Fred Wilson (2012)
https://web.archive.org/web/20140708090402/http://www.chesscafe.com/text/review874.pdf
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
https://chessbookreviews.wordpress.com/tag/most-instructive-games-of-chess-ever-played/
Winning Chess by Irving Chernev and Fred Reinfeld (1949)
https://web.archive.org/web/20140708093415/http://www.chesscafe.com/text/review919.pdf
Discovering Chess Openings by GM Johm 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
Chess Endgames for Kids by Karsten Müller (2015)
https://chessbookreviews.wordpress.com/tag/chess-endgames-for-kids/
A Guide to Chess Improvement by Dan Heisman (2010)
https://web.archive.org/web/20140708105628/http://www.chesscafe.com/text/review781.pdf

the best books to study chess are the following:
Jeremy Silman's endgame course from beginner to master
for chess tactics you should learn all of the tactics by going to youtube or by being a diamond memberbin chess.com you can get videos of everything and I am telling you the videos and everything is great in chess.com that it is worth it. if you want to master chess or at least improve you use youtube or use chess.com diamond membership. you won't have to buy any chess books and trust me you will save alot of money instead of buying chess books.
for strategy the best book I came across is Jeremy Silman's turning chess misconceptions into chess mastery
and for openings you need to know that if you want to be a tactical attacking player for white you play e4 or positional and slow games d4
for black you need to know which opening suits your style. you need to knoe how to defend against d4 and you need to know how to defend against e4
the chess opening explorer in chess.com will teach you how to play any opening and how to play it right.Literally it is like having a Grand Master teach you or use youtube on chess openings and learn from it
again for tactics chess.com's tactic trainer is very good.

just a suggestion. why not keep playing while using other methods (books, tactics, etc.)? i noticed you have not played any correspondence games. why not? it'll give you more time to think. use the analyze feature. you might be suprised how much you might pick up from simple pattern recognition.
in regards to tactics, you will be able to do more of them if you decide to go premium here.

This list contains many books which could be of help to you....
https://www.chess.com/forum/view/chess-equipment/good-chess-books-for-beginners-and-beyond

just a suggestion. why not keep playing while using other methods (books, tactics, etc.)? i noticed you have not played any correspondence games. why not? it'll give you more time to think. use the analyze feature. you might be suprised how much you might pick up from simple pattern recognition.
in regards to tactics, you will be able to do more of them if you decide to go premium here.
I agree with everything above. Also if you get the premium account you will have access to go much more deeply into the Games/Opening explorer at https://www.chess.com/explorer/ and this might help you especially in correspondence games, or when reviewing live games after you've finished
I am a beginner at chess and my tactics rating on chess.com is around 830. My average chess rating on chess.com is also around 800. (in all types-blitz,bullet etc..)I recently learned some opening from the lessons trainer. Please give me some suggestions to improve my position bcoz i am already in love with this game.