Hello I am new

Hi I am new and I am a little confused with how to search things or be friends with people on here. How do I find groups of people who are walking dead fans? And how do I add people? 

I just realized how to join groups so I have joined this one and one for adults with ASD. But I am not sure how to do a lot of other features here. Thank you everyone I hope you are all having a good day today