NOOB Loan Question, any/all help & feedback is appreciated

[John Gallagher]

My buddy and I are placing an offer on our first potential buy today/this week. I am 21, just graduated with MBA, no debt but essentially no savings. Entering a cushy / well-paid W-2 job in September. 

His dad will be putting up the money for an all cash lowball offer, to which we are not too hopeful for a reply/counter. If the owner is interested, I would need to get an investment loan to pay his dad back half of what we put into the house. I am not really sure how to go about doing this, if anyone has any tips. Since we are buying the house in cash, can I still get an HFA loan for my half? Do i specify to the lender what the situation is? Is this a normal thing to be doing? My credit score is around 770. 

We plan to live in this house and fix it up, then sell or use it as our first rental property. It is in a neighborhood we are familiar with, and his father has been flipping and renting for 30 years, so we will have a good base of knowledge to go off. We are also reading as much as possible on the topics, though we are definitely Noobs. I appreciate any and all information. Thanks.