Lastly, generally speaking you can always buy and live in a multi family investment with low down payment options (using FHA as long as you don't have any other FHA loans) and like they mentioned above put 20% down (SFH) and 25% (multi-fam 2-4 unit) for non-owner occupied properties. 

Looking to purchase a fully occupied duplex in Oakland with protected tenants.

Once I had my preapproval I just analyzed deals until one came my way and it had great cashflow potential, it was recently fixed up, and it was tenant occupied with a long term tenant. 

If you're looking to sell it to an owner-occupier, then yes, the tenant has to leave. 

But since it's an abandoned trailer park in Georgia, I"m betting that's not the case.also Also keep in mind septic systems designed for owner occupied use set up to handle RV afferent. 

What rights do we have for access and showing new prospective tenants around an occupied rental?

If savings are limited get your credit score right (if you haven't already - around 600 or higher is where you want to be for a FHA loan) and go this route.Depending on the market, a duplex (owner-occupied where you live in one unit and rent out the other) can pay most of your mortgage while you have the potential to be cash flowing on a owner-occupied 3-4-unit.

I'm stationed at Fort Campbell Kentucky currently but am not planning on staying in the area even though it is a great spot for real estate investing.My plan is to go to college and invest in an owner occupied investment property(looking at duplex's or single family's depending on what type of loan I'm qualified for).

Home owner insurance informed  me l had to occupy the house for coverage or l had to have rental insurance to rent.

What type of repairs are required, how many other duplexes are in the same area, what would be the rent after you fixed it up, are there transit stops near by, do you plan to occupy one side, and how long do you plan to stay in this deal?