Looking for free coach!
I 100% agree with @charmichirag. Noone will help you without monetary benefits except friends,family members, etc.
However, if you want to improve without coach I can give some suggestions .
Anyone can easily get to 1600 rapid if they have a little bit of natural talent and some interest
. I personally can beat 1700-1850 players but yet I don't know opening theory and don't calculate much BUT YOU SHOULD.
1) youtube videos on any topic(openings, middlegames,endgames)
2) lots of puzzles to improve tactical grasp
3)You should have ability to calculate quickly and yet make use optimum use of time.( This hounds tricky)
(Eg I play bullet just to improve speed of calculations for my rapid games