Well, I think you have to define, carefully, what you mean by
"multi-use" and "website" in this context.

Google has a lot of pages that do not require a login.  Those pages are
used by multiple users everyday.  Millions, I'm guessing.  So it's
multi-user but doesn't have a login or any kind of access protection.

I assume you mean support some sort of login, which google has also.
But I thought I'd point out the difference.

So, what do you want to do with separate users logins?  That's the
important bit.  It all depends on your design.  You might want to start
out small, and make a simple prototype first, a smaller version of what
your website will do eventually.

If you could explain a bit more about what your level of expertise is,
and what you are trying to actually do, we might be able to help you a
bit more.