It's great that you are planning for the future (just in case you want to specialize)! As far as clubs go, I'd suggest picking 1-3 that most interest you or that offer opportunities like community service events. You don't want to spread yourself too thin and compromise your study time, grades, etc. I don't think it looks bad if you are part of clubs associated with different specialties. You are a dental student, trying to figure out what interests you. For the clubs at you are in, volunteer to be the D1 representative (leadership role) or try to be part of the organizing team.
If you are open to doing research, look into a summer research program or if you can do something throughout your D1/D2 year. I think it's easier to do research early on, because in your D3/D4 year, you'll have more clinical skills and might be interested in doing mission trips.
I'm actually making a video on getting into residency that should be ready early next week. I'll link it here when I have it up. Maybe it will give you some more ideas.