I'm looking to set up a database where my users can sign up and create accounts, log in and edit their profiles etc. However, I don't want to deal with external database, as with MySQL, are there any available alternatives that are fairly simple to set up? Thanks! :)

Actually MySQL is the easiest.

Yes. I discovered this last night when I set up my first MySQL database, yay! I have always used free hosts which did not support MySQL, so I had to find ways around things. Yesterday morning I bought my first paid hosting and now everything is good to go with MySQL, so I am going to test out lots of things with it, see how everything works. :)