Very noob question (3d model in VR)

Hello, so this may sound very noobish, but I’ve hit the wall. I’m trying to make this 3D character model I downloaded off the marketplace as my character for VR. The model looks just fine, it just doesn’t move his hands or head along with mine. The model stays completely still the whole time just following me around wherever I go. I believe this has something to do with IK? I’m not too sure as I’m still learning. This will happen with any 3D model I try using. Does anyone know how I can make my 3D model move its hands and head the same way I move it in real life instead of just staying completely still? I would honestly appreciate you, this is the only thing stopping me from advancing and there’s a lack of tutorials on youtube. I just feel very goofy because I feel like this is a very basic thing to do and I’m just either not understanding it, or not looking in the right place.

summary: I don’t know how to make a 3D character model into my actual character in VR with movable arms and head.