This is only my opinion, so please don't let me deter you from your dreams. But this is based on my experience…
Walk-ons (non-scholarship, volunteer players) are accepted onto many college sports’ teams. I don't have any experience with track. I did play collegiate softball & we had walkons, but they all had experience in their sport; some were quite good. Very few ever got to play in games, however. Track may be different, I don't know if track teams carry reserves or practice players. In some sports, walk ons may not even dress for events- they are strictly for practice. If you are a natural runner, etc you may be fine to have no competitive experience. Sometimes, walk-ons are starting players and maybe move on to earn a scholarship. All you can do is ask the program- they will let you know if they have open tryouts for walkons.
If you are at a smaller college that perhaps needs numbers to field a full team, your chances as an inexperienced athlete to make a team probably aren't very good but would be better than at a major university with a fully-funded and staffed program. Bear in mind that if you make a team, colleges have to pay to feed you, equip you, & transport you to competitions (I’m not talking about scholarship athletes, who get also some form of tuition, room & board, and books assistance), plus coaches will have to invest time with you in offseason/preseason/regular season workouts. There is a limited amount of funding to do that. They are probably only going to accept athletes who can help them succeed in the meets to justify the expenses of them being on the team. And this should probably have been mentioned first… student-athletes are supposed to be students first. Travel for college events is almost always out of town. It is difficult to maintain your studies with weekly absences due to sporting events (even more so for walk-ons who usually also have at least a part time job to pay for college).
If you aren't at the top of your game but love to play and want to participate in sports in college, I suggest looking into intramural or club programs. Many schools have them in a variety of sports, including some that are not offered at a varsity level, with recreational leagues and events open to the entire student body.
Having a love of the game and the heart to work hard (and college sports can be a lot more like a job vs a recreational activity) plus a willingness to be part of the team instead of being a starting player are all qualities that help teams succeed and are welcomed by coaches.
If college sports are your dream, go for it, but realize that it will be a difficult journey and will require a lot of luck and the right situation. Even without being on a team, please continue running- try some local 5Ks or other races, and keep running because you love it and it is important to you. Good luck.