Beginner advice needed

Hi

I've got a specific video project in mind but being new to this don't even know where to start in terms of the feature set needed for the software to do the job.

Mostly I need to edit existing footage to change a persons position in the scene (or object) while the rest of the content obviously needs to remain, so a bit of background editing needs to happen.

I've been a long time user of Adobe PS and the print range of products -- but moving to video don't even know the technical terms for what I'm wanting to do, so any advice or points in the right direction would be most appreciated.

Thanks, Simon