Perhaps a 20% mortgage with a 10% line of credit?  

My friend has home construction experience and I have a good credit score with a desire to learn.

@Todd Willhoite  Desktop Underwriter® (DU®) provides lenders a comprehensive credit risk assessment that determines whether a loan meets Fannie Mae’s eligibility requirements. 

I am from Waukegan, Illinois in my late twenties, working for a credit union at the moment.

I own a small IT Consultancy business in MD and have a good credit score.

My question is would I be able to get a HELOC on this property (home equity line of credit) and what happens if I move but keep the property as 100% rental.

As I sit here thinking about creative ways to fund a deal, including hard money, I have come across the idea of a Solo 401K plan and loaning to myself from the plan.Key facts that I can find are:  5-year term (normal prin+interest payments required at least quarterly), Larger of $50K or 50% of vested balance is the max loan, no credit check or specificity required about intended use of funds, failure to make payments/payoff on time are that plan treats it as a taxable distribution (early in my case), can loan at a reasonable interest rate which sounds like can be a prime+ type rate.....last WSJ prime was 3/22/18 at 4.75%. 

You learn so much on the first deal and hopefully this will spring board you to life long real estate investing to build wealth.I would use the line of credits and forget the other financing. 

As I've been hunting for the right duplex-fourplex, I've gotten as far as applying for a deal I'd found, only to find out my credit wasn't sufficient.My goal: purchase a small multi-family unit needing a light-medium amount of rehab, but I don't want to come out of pocket very much.First Question:  What options do I have?

Yes, you will have to put 20-30% down (you can get creative and ask the seller you carry this portion if you don’t have it, ask friends and family, partner with someone, etc.) and your credit and DTI must meet the bank requirements.