I have been doing competitive coding for 2-3 months now, and i am able to perform good on codechef but for some reason not good on codeforces. Some of the problems i faced was Getting AC at one go ( my score always suffers due to penalty 
) , or solving problems faster. Any tips on how can i also get better at platforms like codeforces ?
‘Speed’ is all you need.
Don’t dare to compare Codechef with Codeforeces. These two platforms differs in various ways example your current increase in rating have nothing to do with your no. of contest attempt on Codeforces whereas on Codechef it does.
But in your case I think you need to think of solution faster because there are so many people register on Codeforces for the contest. Also there you will be facing pretest. On Codechef you don’t. You will become (may) used to it after atleast 10 contests.