I would like to know if it is better to sell to an investor (as-is), or try to make repairs to bring it up to market and sell to a potential buyer (to live-in) instead?

There is also many Private Money Lenders the buyer can get. 

We are first time home buyers and looking to someone who is interested in helping people find their home and we would want him/her to make money. 

I am a first time home buyer in a partnership where I am taking a conventional loan to purchase the property, and my partner is contributing half the value of the property in cash to pay the downpayment, closing costs, and rehab.

Also I keep seeing videos of realtors getting buyers or leads in general from Zillow and Realtor.com what are your thoughts on this?

Run the numbers and remember you want the best deal for your buyer as possible.  

The buyer made it clear she wanted to refinance it in a year once she improved some credit and could acquire an FHA, which I was fine with.

Let's say I'm a buyer, trying to purchase a property.

This is one potential way to protect sellers from buyers who take homes subject-to and then default on the mortgage.

Tenant-buyer must exercise their option by day 180.2.