If I wanted to host a game on let's say, Steam Counter-Strike, what setting to I need t use for port forwarding to let someone I know login using my routers IP address. I options are TCP/UDP, TCP, & UDP. Also, what should be my starting and ending ports? Thanks.

You need to look that up with Steam for this game, or it may be configurable so you can set the port yourself, and then forward that. If the game only needs one outside-visible port, then the start-end points would be that one port. If the game can take both TCP and UDP connections, then depending upon the router, you may have to enable those separately, but using the same port.