How to join the coach slot

Type .coach t or .coach ct in chat on your team's scrim server. You then coach the team on that side and watch them play.

Join as coach

Connect to your team server. Start your SCL server shows how to get the connect command.
Wait until an admin has typed .match. .match clears every coach, so a .coach typed before it is lost.
Type .coach t or .coach ct, for the side your team is on.
Type .ready as well. The match waits for every player on the server, coaches included.

Anyone can coach, and a team can have more than one coach. Coaching works only on team servers, because personal servers have no match mode. See How to play CS2 Scrim mode.

What a coach does in a round

Coaching starts once the match is live. In warmup you play as normal.

Spawn invisible and frozen in freeze time, with no weapons and no money.
Spectate your team from the end of freeze time.
Stay out of the game: you never get the bomb, and your stats reset to 0 every round.
Follow your team after halftime. The coach belongs to the team, not the side.

Stop coaching

Type .uncoach. Ending a match with .endmatch clears every coach too, so type .coach again for the next match.

If it doesn't work

Chat says Coach command can only be used in match mode! The server is in practice mode. An admin types .match first.
Chat says You are already coaching a team! Type .uncoach, then pick the other side.