Thinking about my first purchase, slight issue.

[Mike Robbins]

I have been thinking about real estate investing for about 2 years now have read a lot of articles and watched a lot of videos.  Finally found a property which looks good on paper, it's a duplex and I plan to live in the upper unit and rent out the lower unit and take it from there.  Kinda test out the waters first and see if I have a taste for it while making it much easier for me to pay off the mortgage on my first house.  The one issue is that both units are currently occupied, I was wondering the legality of me having to give one of the renters boot in order for me to move in.  Would I just have to wait until his/her lease is up? Any additional insight or info for a newbie like me would be greatly appreciated!