Hi Dannielle!
Im currently going through the same process and I had the same questions as you do now. I started by getting in contact with a Bigger Pockets member. He was kind enough to have a 35 min phone call with me and answer some of my questions and guide me into how he does his investing.
I live in California and I wanted to invest in Phoenix Arizona. The market there is pretty hot. Houses don't last long on the market and rentals aren't as profitable for a buy and hold.
So here is what I've learned so far, ( keep in mind I am still in search for my first deal) you find your market by educating your self on that specific market. You can hear somebody talk about it or you can take your finger and click somewhere on the map on Zillow. Learn about the population growth, Job growth, Job Oportunities, Universities, Constructions, and crime of the area. Then you will formulate your own opinion on that specific market and decide if that is somewhere youd like to invest in.
The Midwest is great for cash flow not so much for appreciation but your money can go along way over there. Im personally looking into buy and holds in Wisconsin. Im also trying to decide if I want to buy a Turn Key property as my first out of state purchase just to get my feet wet. But I still haven't decided because that will stall me from BRRRR ing. Im also interested in Las Vegas for better appreciation but the market there is pretty hot as well.
Also, once you find a market you might be interested in, calling realtors and property managers and asking them questions will help you get more educated faster.
I hope this helps a little.
For me finding the market to invest in is the most, if not only, tedious and boring part of this all.