In practice if you barely know how to host a server that responds to requests, most solutions won’t work for you because they require writing code that assumes you know somewhat more about how it all works.

I would frankly recommend biting the bullet and doing some heavy reading and trial and error. All of the solutions I know only get you out of the business of storing/managing/checking passwords or MFA. They don’t get you out of anything else.

If you just need something quick and dirty and not "best practices", you could configure HTTP based authentication (over HTTPS) through a web server like Apache.