How to decrease the "resolution" or amounts of vertices in a 3D scan? I tried a few days ago to 3D scan an object and also my own face.

The scan includes crazy amounts of vertices and My computer probably isn't the best.

How to decrease the "resolution" or amounts of vertices in a 3D scan? As I said, I'm fairly new to this, so a "for Dummies"-guide would be awesome! Hopefully there are some add-ons or something that will make this process easy
Hope some of you can help!

Sincerely
Andreas
Try decimate modifier. Also face\tris to quads in edit mode, before decimating.
https://docs.blender.org/manual/en/latest/modeling/modifiers/generate/decimate.html