Beginner Questions Please: Which To Go With ?

Hello:

Am about to sign up for an on-line database course (introductory)

Apparently, one must have on their PC for the course either

Access
postgre
mysql

Am really new at this.
Access is a problem, as the package costs is $200.00 Wow !

I downloaded postgre, but I am a bit stumped on
what to do next.
The problem is I'm totally unfamiliar with ftp downloads.

There are a bunch of folders.

What do I open, or do next, please, to get started ?

I would like to evaluate postgre and mysql before the course actually
starts.

Also: what are the major differences between all 3 packages ?

Which would be easiest to learn for a true database beginner ?

Should perhaps I go with Access despite the cost ? Is it "easier", or are
the screens and interface 'better" ?

Want to learn one database fairly well, as I think it's something I should
know, and would also look good on a job resume.

Thanks,
Bob

lease, to get started