OP folks in here are trying to give you legit advice and you're handwaving a lot of it. Listen to them. You're not the first nor the last person to have this idea. You can ignore all of the advice if you choose but I urge you to not ignore this one.

Hire a red team expert or service to scan your site and provide you with a report. Letting others upload content to your server is a minefield. Take the advice seriously.

It's a cool project. And I urge you to keep learning and making cool things.