Hi Cole-
If you're starting out, I'd say the best place to invest is where you live (or where you have lived). I currently have 24 doors across 5 buildings here in Denver, and the key to starting out is finding value where others don't see it - which requires you be on the ground in the market where you are investing. Books and reports focus on the quant side of things (and Brandon's are good books), but only by driving and visiting can you get a read on the qual side.
There's the allure of smaller price tags offering higher CAPs, but when you factor in the economic risk (which is why the price tags are smaller) and the risks of remote management (which are significant) it doesn't seem worth it - at least to me. It feels a bit like the penny stock approach to the stock market, which fails far more often than it works.
Down South, Colorado Springs is a bit over heated and there's some real garbage, though I've seen some interesting opportunities in Colorado City. Fort Collins isn't bad, though it's getting close to Denver pricing based on Boulder proximity - and Denver is stronger. Greeley has been on a tear and it's a boom/bust oil town so I'd avoid that for the moment. If I were starting, I'd take a hard look at Englewood where you can get Denver rents at a discount per door. Depending on your situation, best way in is to house hack a duplex or SFR with an AirBnB angle (present craziness aside).
In terms of next steps, get yourself an underwriting template and practice evaluating deals you see on the MLS. It's not difficult, and it's a practical necessity if you're looking to get into investment real estate. For properties that look good on the numbers, drive them and practice evaluating neighborhood and condition.
Best - Ian