I just found this genealogy site and just now found my family member’s name on the list. This is an unusual question, but how do I find the actual tribe that my family member was a part of? I’m guessing Cherokee, but how can I confirm that?

I suggest you go to Ancestry.com and sign up for their DNA test.

https://www.ancestry.com/dna/?s_kwcid=ancestry+dna&gclid=CNffya_f3tQCFUeHswodVfYLMQ&o_xid=58712&o_lid=58712&o_sch=Paid+Search+Brand