Blender avatar movement, animation, and sound simulation

I want to do interviews with people whose avatars I will download from TurboSquid or their competition with background, furniture, etc. to look highly realistic. I want them to sit, move and quake a little like humans in a two-way interview (the avatar will interview me, where my background will be the same room as avatar, some side shots of two "people" sitting a few feet from one another). I want to provide a vocal script for the interviewer with a voice over that sounds as similar to them as possible, same pitch and timber. I can download sound of them uttering all vowel sounds and consonants.

I did Maya and Lightwave for many years, but cannot afford them. I need some live Zoom or Team Viewer tutoring on how to upload rigged model/avatar to Blender and move, keyframe, etc. and add sound track. I need to know how to simulate voice.