@Courtney Warner
Welcome!
There are numerous ways to find out repair costs - a good book, fantastic really, to read is Estimating Rehab Costs by J Scott. Once you get a good base from either that book, or other forums, blogs, etc - find a good contractor in your area and pay them $100 to accompany you to to a property to go through the necessary repairs and typical costs. You can find a good contractor either through here on BP, using Google and reading reviews, or through FB groups where you just search your city and REIA in the search bar. Almost every city has one of these if not multiple.
Use the same technique to find a good Realtor in your area - they will help you immensely with being able to determine ARV's. Most of this information is available to you already, however, via sites like Realtor.com, Redfin, Zillow, etc. You can pull recently sold (within 3-6 months) properties and filter down to similar bed/bath & sq footage. Obviously, the closer the comparable property, the better. General rule is to not go out more than a mile radius from subject property unless you are very rural.
hope this helps!
Ryan