my actual playing strength is 1750 as on chess.com of course on my uscf rating it wont show since i dont take it too seriously. but to b honest if i did they would match each other very closely. so i think chess.com rating n uscf rating r very close to each other

there is a big I do not care factor. I do better when the pressure is on so in USCF I play better

The best way to figure out what your USCF rating would be is to play some OTB tournaments :).  Find a club near you, its not that scary I promise.

My USCF rating: 1200 (1189 to be exact.)

My Chess.com Turn-Based rating: 1400 (1380 to be exact)

My Live Chess Bullet Rating: About 3 weeks ago it was at 1622, but nowadays i'm 1402 bullet.

My Live Chess Blitz Rating: 1325

My Live Chess Standard Rating: 1275

Yes, USCF does not use glicko. If they did, chess.com and USCF would be pretty close. USCF does have a feature for new players called provisional ratings though, where the rating does fluctuate a lot. 

It's true that your CC rating doesn't directly predict your USCF rating, or vice versa, but it's silly to say they aren't correlated. As discussed in other threads, CC turn-based ratings tend to run ~300 points higher than USCF, give or take. There are exceptions but that's the trend.

(My USCF: 1531, CC: 1890)

How to have a USCF rating?

Are we assuming people are taking their time in correspondence though? Or just playing as fast as they would in bullet lol. 

Easy.  Play in USCF tournaments.

http://main.uschess.org/index.php?option=com_wrapper&Itemid=199

My blitz rating is 1366 and my uscf rating is 1800