Yes, just download the Vassal Engine at the website. You will then have to download the CC:E module and any other CC modules that you want to play.
For opponents, I would browse the forums on this site, many contacts here. Also, check out the Combat Commander Vassal Tournament Guild, many players there. You should have not have a problem finding opponents of all stages of experience willing to play on Vassal. The CC Vassal modules are great!
Also, you can go to the CC:E main room on Vassal and look for a game.
If you think you'd also like playing Uno or Slapjack via email, then send me a Geekmail.
I am currently in two email games and actually enjoy it. Though those turns where you're waiting for an opponent in a different time zone, or who works different hours that you, just to say if they have an Ambush or not can be trying.
I like it because nothing makes me happier than to come home from work and seeing one or both (or three if you decide to try it this way) games waiting for a critical decision (such as: Do I discard AGAIN!?).
Anyway, long answer to say I'm interested in email games, if you are.
With two kids finding the time to play live is a bit more challenging. And usually when I can, I have a local friend Jonesing to play FTF. :-)