Yes, you will be bad and people will talk shit. People also talk shit when you're good. I made a dumb mistake and lost a clutch while carrying my team with 15+ more kills than 2nd fragger. They instantly started throwing hate in voice/text. Have thick skin, mute/block comms if they persist. If you want que up with me. I dont shit talk and when people on my team do I usually tell them to cut it out and they usually listen or I will just TK them or vote kick and carry.

If you haven't check out TheWarOwl videos on youtube please do, they are entertaining and instructional.

Memorize all the callouts on a map, run the map empty to get used to it, calling everything out as you do as if you were in game. If someone on my team cant get a frag at all but they have solid callouts I'm super happy. Callouts are number of enemy seen, where, and where they are heading. Whether they have bomb or an awp is relevant too. For instance on Dust II if I'm CT at B and peek tunnels and see 2 upper tunnels, I will call: "2 upper tunnels." If they kill me and I see them push B and a third comes: "3 pushing B." Make your calls quick and accurate. Especially your after death cam, right after you die those few seconds of enemy movement you can see can be critical if called correctly. Save any non immediate match-relevant talk until the round ends. I hate it when teammates are bickering over chat while I'm trying to listen for footsteps.

Learn smoke grenade spots for CT and T on maps. If you cant get kills but nail your smokes everytime you are still contributing in a big way to the team.

Practice aim and stutter stepping. Watch tutorials, download workshop maps, it helps.