You state that you are buying a house right now with owner financing. You want to know if you can get a HUD Loan or find first time home buyer programs.
First off, HUD is actually the government organization that helps neighborhoods develop and assist with loan guarantees to the banks. HUD stands for Housing and Urban Development.
So HUD and FHA work together to help people like you and I to own homes. FHA was established in 1934 as the Federal Housing Authority. So together they offer loan guarantees so the banks will lend you money on low interest and down payments.
If an FHA loan defaults, HUD then takes it over and offers it for sale on the market. That is why they are called HUD homes. It was a home bought with an FHA loan which the person defaulted on and now HUD will help get it sold again.
So the answer to your question about getting a loan on the house you are already buying, yes you can if you have sufficient credit and equity.
The only way you find that out is to have an appraisal done to determine value. Then you need to know your credit scores to see if you can qualify for a mortgage.