I want to join a jam and be part of something and maybe a team, anything?

You could join any jams but if you want to join a team, you need to tell others what you can contribute to the team. Something such as coding, art or music is great thing to offer.

And if you want to join a team, you should probably join a more popular and well known game jam (like the featured jams) that have a large community of participants also looking for teammates

Some jams have a Discord; those are good places to find other people to team up with. 

Joining a jam is very easy - go to the jams page and find one (or more) that fit in your interests and skill set. Some are open to any kinds of games; a lot are more restricted - specific themes, or specific game engines, or tabletop games only, and so on. Some encourage teamwork; some don't allow it. 

Finding a good team for collaboration is likely to take some time as you get to know people, either in the specific game jam community area, or in Discord or similar places.