You can join as many as you like. They won't care how many others you have joined. Give it a go, and see which ones you like.
What tends to end up limiting people is their actual involvement in whatever clubs they have joined. So I perhaps joined about 10 in my first year, I was actively involved in the activities of maybe 3-4 (in terms of attending events etc), and the others I just got the emails, used discount cards if they had one etc, but didn't really end up getting involved in them. Down the track I ended up being heavily involved in 1 society (ie. on the committee, helping to run it), and attended events of maybe two others. It all just depends on what interests you, how many events are run, and your other time commitments (eg. class/work/study etc).
All the clubs are very different in terms of how frequently events are run, and what kind of events they offer etc some clubs will by their nature have a level of attendance that is required if you join and want to be a member (eg. if you join a musical society/ensemble you better go to the weekly rehearsals
) but most clubs don't have those kind of requirements/expectations.