I have a tree that is probably citrus and hasn't started bearing fruit yet. I've lived here for only a year and don't know how old the tree is
The leaves appear to be trifoliate. The portion of the tree that has such leaves will be Poncirus or its hybrid (citrange). If the tree is grafted then it's possible that grafted variety has died and all that remains is the rootstock. Look for leaves that are not trifoliate.