Hey Newbie-
you've come to the right place.
there are some great resources you can find by just googling "best way to maximize SPG" or something like that. Most of us have a lot of different cards, either to get the sign up bonuses or to maximize the amount of points/miles you get using the card in different type of places. In my opinion, and im sure there are other opinions out there, in your case the SPG is the way to go!
good luck and just keep reading!