You want to do / can do a couple a things:
1. Make sure it's really super simple stupid easy for people to upload their videos. You'll need to do lots of user testing to make sure anyone can upload their stuff. Make sure you call it out and ask people to do so.
2. You can gameify it someway. Example, you might start by giving people a 10% discount for uploading a video.
3. You can seed a few videos. People tend to do things when they see others do it. You can use your staff to do it and show it off. Or you can send free merch to bloggers/influencers and ask them to make videos. You can't force them, but this can seed your pages for a start. I did something similar years ago, and it was very successful.
Hope that helps!