Hey @Melissa D., best of luck as you start out with investing.
I'm a local investor and I've owned rental properties in Florida as well as Colorado. Now that I've been investing in rental properties for 20 years (and running a local PMC), I have learned a thing or two.
Re: your questions -
1. If you're local to the Denver area, what is your favorite networking group/meetup and why? Are there any you would avoid?
--Unpopular opinion on BP, but I would skip the networking in your situation. I've experienced enough of this to know that the people who have real credibility don't usually go to these. There are exceptions, but generally I would say this is a waste of your time.
2. If you have purchased an out of state investment property, what were your biggest lessons learned and were there any surprises during the process? (I'm currently reading David Green's Long-Distance Real Estate Investing book.)
--You can get a "great deal" buying property in Alabama, or Oklahoma... I guess? But you will never see the appreciation that truly builds wealth, because those low-barrier-to-entry properties will stay flat on the metric that matters: appreciation.
There are SOME exceptions to the extremes of Colorado and Alabama. Probably Idaho. If you do your research, an out-of-state investment can work, but you need to know exactly how to hire a PMC (most get this part wrong) and you need to ask a vetted PMC what they would buy in the area and what it will rent for. Don't buy and then hire a PMC, find the PMC first. They know everything about the local market that you want to know.
Yes it's very expensive to buy in Colorado, and that's not changing anytime soon. People want to live here, demand will remain high, and appreciation is how you build wealth (not cashflow.) Building wealth in real estate is a long game, there are no shortcuts.
3. What is your favorite real estate resource (i.e., book, podcast/episode, tool, etc.)?
--Again, unpopular BP opinion, but books are written to sell, podcasts are made to generate subscribers, etc etc. There is knowledge to be found in these media forms, but knowledge isn't their first motivator.
If I start a property management podcast or YouTube channel tomorrow, it will be to make money not to educate you. I will provide useful information along the way, but getting subscribers is the number one goal, and to that end, most of the talking heads are going to make investing sound FAR more sexy and lucrative than it really is.
The money is in selling a dream, not selling a map.
Final bit of advice: if you can, steer clear of house hacking and multi-unit. I could write an essay on why, but as someone who manages nearly 1,000 doors up and down the I-25 corridor, I can tell you these are not the investment vehicles I recommend to my clients and they are not what I personally would ever own.