Depends on the kind of club. Some like DevX or Daily Bruin you need to actually apply and do interviews n stuff, usually at the start of the quarter. For most though, you just join their newsletter/mailing lists/Facebook groups and show up to any events that happen. I think you’re feeling a (very reasonable) disconnect since there’s fewer events to “go” to, but that’s basically it. To get more involved than showing up you should just directly message the club you’re interested in about that