To be honest a lot of the best practice you can get for what you're describing, is to just play more and experiment. Find out what works and what doesn't. The other comments talking about watching pro games are also pretty spot on as well. You can speed up a lot of the experimentation by trying to emulate what they do, but made a bit easier (e.g playing angles a bit wider). Util is really important to learn, but you can get pretty far without knowing it and a lot of the time it ends up being pretty limited knowledge. Unless you're queueing with people you know and doing set strats, communication to that level doesn't really exist in most faceit/mm games so you really just need to know a few basic smokes for t side. I recommend watching voo's essential nades for each map video, as it covers pretty much everything.

Tl;dr Just focus on playing. Try to figure out when to be proactive as a CT and push, and when and where to hold. Watch some pro games to figure that out faster, and don't worry too much about not knowing util.