Insert values into MySQL database (JavaScript)

I’m working a sign up function but have no knowledge on PHP. Basically I want to insert all the info in the signup onto a database like all sign up forms do. Then the login function will be able to check if that information is already there. Anyway, I’m a noob at MySQL so how would I approach this? I want to use vanilla JS and not Node or other stuff. I’ve heard it’s possible to do this but I don’t know how I would go about doing this. Sorry if I didn’t explain this well; First post on Stack...