Have a Realtor help you with ARV. Ask around for an investor friendly Realtor. Look at what they send you and learn from it, don't just get the number and run- learn, and become less dependent over time. If you agree to sell with the agent when you are ready, they should be willing to put some time/effort into it (but remember their time is money). Comps are not as simple as people think. I have seen a lot of flippers in my area lose money, or not make much, because they inflated the ARV and/or didn't account for market changes over time. Your biggest challenge beyond correct comps is time. When you say "live in" flip, do you mean you expect to be there more than 6 months? If so, your comps are going to be extra challenging especially now as most markets are starting to shift away from the current "low inventory/high demand" pattern that has been prevalent lately. Again, a Realtor can help with this. Be useful to them, be diligent and listen to them, build a relationship and they can be a great ally.
As for repairs- once you have a picture of comps- look at those houses. What finishes do they have? You want to be level to those, maybe do a little bit extra, but not overspend. Read J.Scott's book on flipping houses. Understand how you come up with a scope of work. Talk to other investors- get names of contractors they work with. BE CAREFUL. Any work you are not doing yourself, proceed with caution. Never, ever, EVER pay for anything 100% up front. I don't even do 50% with my contractors, but it depends on the job. Get multiple bids. Doing a fix and flip right requires WORK on your end, and by that I don't mean the actual construction. I mean that especially in the beginning you have a lot of legwork to do and a lot of people to meet and talk with. Don't make the mistake of thinking that flipping a house is all about the mechanical aspect- it's as much about the logistics, people management, design, and marketing.
GOOD LUCK! Proceed with caution, educate yourself, and network- and you will do fine.