Be wary of suggestion 3. Raffles come under gambling or games of chance in many states. If you decide to hold many raffles, you may find a state government agency breathing down your neck.
Wow. I hope you got a degree in a field that will allow you to repay your loan(s). You've got a good outlook, but... wow... That's a tremendous "amount of return" you need to get for that degree right off the bat. Not a great way to be starting out in the world.
But check your statements on those cards you've tossed in the drawer. Make sure they don't charge you an inactive fee or a yearly fee.