So just to be clear two of the units have tenants, and my family is occupying the other two units.

So it is not a viable loan for non-owner occupied investment properties.I have 2 recommendations for you:- Define what you want from real estate investing short and long term- Look into house hacking your first deal. 

In such cases, the local fire marshalls may have authority. some jurisidictions require tanks to be cleaned out and filled with sand or other inert substance. some require sampling. you can check with the local fire marshall without identifying the house.Again, you should find out why the tank is not used. if its because the seller no longer occupies the house, then the tank may still be able to be used. sometimes, owners decide to put a tank in the basement. you should find out if it is truly an abandoned tank or just temporarily inactive because the seller is not using the house....  

I would like to take over the property before the bank takes any action, however I have no idea of where to star...My godmother occupies one of the apartments out of the 3. 

Owner Occupied you say?

Personally, I am not a big fan of third party payers (Section 8, insurance companies, etc) but it is a niche plenty of people occupy successfully.

The lender/underwriters will have questions about your intentions to actually owner occupy on the FHA loan.As for team: many of us agents have great lenders and contractors, I can connect you with a good PM as wellAreas: LOTS of areas that you cant go wrong, I really like southwest denver for affordability and access to downtown. 

Is the property occupied or vacant?

@Frank NguyenIt is illegal to purposely turn off a utility while a tenant occupies the unit.  

My only previous experience with lenders is with mortgages on homes I've owned & occupied, not REI properties.