Your category will be based on where your target would fall into.
If your target is a known personality, then they would fall into one of the following categories:
Film, TV & Theater
Musicians
Athletes
Esports
Content Creators
Activists
Government
Companies
Business Executives
Other (Known)
If your target isn't a known personality, but is rather just an everyday person, then they will be listed in the Everyday People category.
If you want to target anyone willing to do what you're proposing, then make sure to choose an Open Call campaign and it will be automatically listed in the Open Call category.