Not sure on the following...

I'm open to do a 1v1 this SmackDown! but don't know how I would go around doing it/go around confining in a member

Well if you want to do a Smackdown match with someone, you should check the recent Smackdown card, and see who has done a match. When you know who has done a match and who hasn't, you can check out the roster, and all of the gamertags are listed at the bottom of the page with the superstars they use. You can send them a message through Xbox to see if they want to do one.

Or if you don't want it to be complicated, go on the Xat chat, on the homepage of the website to ask anyone who is online if they want to do a match.