This page has some information about Fitz's ability with the Skill and the WitBasically the Wit gives Fitz an awareness of animals in particular, but also of humans. He can reach out wordlessly or with words, to animals in particular. He can also do a general
repel which is a self-protective thing (that's usually reflexive; he doesn't do it much these days as he has a lot more control). This
repel can make someone step back, like a dash of cold water in the face. There is an ability to attract / calm with the Wit, too, but at this point in canon Fitz doesn't actually know how to do that. He might learn at some point. If you might be interested in Fitz doing that with yours, please let me know.
Even canonically, if he reaches for someone with the Wit, they won't necessarily answer him. So if your character is non-human, they can ignore him, or push him away. But they could also choose to instigate communication with him that way if they wanted to.
He has a general sense of all creatures (incl humans) as being part of the web of life, so he might be aware of someone even if said someone thinks they're hiding from him. This is an OPT-IN ability though! Please let me know if it's okay for Fitz to be aware of your character, if he wouldn't be aware through normal methods.
The Skill is more about touching someone, a human, mind to mind. (The Skill and the Wit can overlap though.) There can be some psychometric ability too, and some general ability to influence. E.g. one time he canonically builds on someone's need to pee and broadcasts that to a group, to get the group meeting over with.
Basically, if you are open to your character having some interaction with him via the Wit or the Skill, or if you have any questions, please let me know. Otherwise I'll assume that it's only the basics. Thanks!