Now that I'd been learning CP for around 2 years now (I'm bad at it though), I decided to hop on Codeforces and start doing contests for Div. 3 and Div. 2. However, I wasn't able to go through the full problemset of these contests before going offline because of my timezone. Besides from doing other contests in virtual mode, I decided to also start learning and doing problems on CSES Problem Set to improve my CP skills. Have any of you ever had such experience or anything similar? Should I grind problems on CSES Problem Set? Please give me some advice on whether or not I should seriously learn CP from CSES, I'm having a very important exam next year that requires CP skills so I have 1 year left to prepare.

P.S. Sorry if my language feels rather unnatural, English isn't my mother tongue.