I also took a gap year, as I was in a similar position as you when i graduated high school in 2020 at 17 years old. Luckily, during my gap year I was able to train at a high level and my high school coach continued to work with me/provide me a "internship" opportunity for which I worked as a social media guy for his pro team.
I think you are thinking about things in the right way, and it is pretty clear that you have desire to be good and the drive to hold yourself accountable. To be honest, the thing I would encourage you to think a lot about would be what you would do when you aren't training. Even if it's getting a job at a coffee shop, giving yourself structure will ultimately ensure that you are holding yourself accountable/being intentional about when you train and what not. It can be very easy when you are by yourself to sleep in, run in the evenings because you have put off your run all day, and be mentally unstimulated. A lot of the advice on here has been really good (ie making sure you have a clear racing schedule, be smart about training, etc). In terms of college recruiting i would recommend reaching out to coaches sooner rather than later, and obviously the first step would be running as fast as you can this outdoor season. Given that you are already a 9:00 2 miler, you should be able to get some decent attention from coaches, and in terms of recruiting, you can look at the rest of this season as your "junior year", as that's when times matter most for college recruiting.