You don't say what device you're using-- is this an iPhone, a Mac, an iPad, or what? What OS are you using? Here are some general things:
In macOS, iOS, and iPadOS:
You can include names in the Caption field. Then that picture will show up in a search. However, that won't add the person to the people albums.
In iOS and iPadOS:
If an object isn't recognized as a face, then it can't be named using facial recognition tags.
macOS
Any object, face or not, can be "named" using the circled plus sign in the face section of the Info Window. That will add it to the appropriate "People/Pet" album or it will create a new album for that ID. You can also include names in the Keyword field. This manual ID won't help in making future recognitions. A Smart Album can be used to collect the keyword or caption names into a more inclusive Personal album.
With more info about your situation, we can give more details.