I do not know to what extent my experience entering university as a 17 year old would compare with your experience entering as a 15 year old.
In my experience the academics were not particularly difficult. The academics (at MIT) was a big step up from what I was used to in high school. Freshman year academics were however not all that hard.
The living culture and living away from home as a young kid was more of a challenge. You might find this also as a 15 year old “on your own” for the first time. However, different people will have different experiences. Also, if you are entering university with a full year of college credits at age 15, there are not a lot of people in the world who are “like you” which makes it a bit harder to predict how things will go.
One thing to think about is whether you want to take a gap year. You could apply for admissions, then defer for a year. Of course this would go better if you can think of something productive to do for the gap year.
Another thing to think about is how far from home you want to go. There may be some advantages to being a short car ride from home. If there is an appropriate good university within an hour or so from your home, it will still be like living in a different world when you wake up in your dorm room. However, friendly faces will be reachable if you want them.