@Brian Rowles I 100% understand the fear and questions around estimating the ARV. *Full disclosure* I am still early in my journey but the only way I know to determine ARV is to look at comparables (comps). This will give you a range of the possible value and you will have to determine what you are going to use for your analysis. You can use Zillow or other MLS sites to see what houses of similar size are listed or recently sold for.
Odds are that you personally know a realtor. Reach out to them and have them do a quick analysis of the property and the area. This will help you build your knowledge base for that area as well as add someone to your team who is looking for properties for you.
@Brian Rowles are you intending on keeping all the properties or flipping some. If selling some of them get a realtor involved once you have a contract on them or before if you know them well enough. That's the best way for anyone new. Let them know they will be listing the property once your ready to list so they have incentive to help you out. Comping isn't that hard but little mistakes can make a big difference.
If you aren't ever selling and just plan on keeping then either pay the realtor for their time ask for a bpo. Or get with a local mortgage broker than can help you refinance your first few properties and they will be able to help you (or at least should) with value, they have to know value to be able to see if its worth even getting an appraisal. A good broker will know the values and be able to do a quick desktop appraisal which isn't perfect but will get you close.