Hi, Thea-Mari, welcome to Wikitree.
You could contact your greeter, Karen Finnerty using the link below her greeting message on your profile page. Greeters will have all the info for becoming full members. If I remember correctly (and someone will correct me if I am wrong), to become a full member you need to sign the honor code, to get more editing abilities. It's been a while since I joined so there may be other steps, I can't recall.
To add family, go to your own profile and click the "Edit" tab at the top, there will be links down the right hand side where you can add to your tree.