@Jesse Stanley
There are MANY pitfalls along the path to a successful real estate business and unfortunately you stepped in one right off the bat. It's always best to ask for advice here on BiggerPockets on any deal that has some special circumstance like this one (occupant/renter) BEFORE you pull the trigger. Mike's right about your options. Unfortunately, the renter doesn't have to cooperate with you at all. This is likely a bad situation for him or her so I would not expect them to want to help.
One strategy that you might have heard kicked around B.P. is "cash for keys". What you would do is make contact with the renter (in person if necessary... but be careful how you do it because you can be charged with trespassing) and offer to pay them to leave. I've heard of people paying up to $5000 to get someone to move out. If this is a wholesale deal that you hope to simultaneous close and not put any of your own money in, you're in a tough spot. I would strongly advise you to stick to really simple, low-risk deals until you've got some more experience.
I hope it works out for you.