If need 2 more people to help complete an action.
Is it possible to delete unnecessary character data?

Any advice will be appreciated! Thank you!

Hi
Do you mean you need to track only 1 actor, but there will be 3 men at the scene when shooting a video?
If that is the case, then you just don't need the multi-actor tracking. Create a project with single actor and align the model with appropriate actor on video to start the tracking. Of course, having other men in the view will put some confusion to the program, so you can expect more tracking errors. But it should work.