It is going to be hard to do it solo. If you can find a group to join, that would be best. What part of the country are you in? Might have some suggestions from people if you post where you are at. If you are in a big population center, you won't be the only guy in your area with a similar goal.
If you can't find a group to train with, the next best thing is a handful of people to do occasional runs with, or an occasional workout with, even if they can't keep up with you on the track workouts. 2 days a week with somebody else is so much better than 0 days a week.
If you can't find even that, then get a friend, family member, or gf or whatever to go to the track with you and time your track workouts. If they are a former runner, they hopefully will understand what you are doing and be willing to help you push through those workouts. This will be better than being completely alone on the track.
If you can't find even that, better learn to like being lonely for a few hours a day. It's not impossible to run fast training completely solo, but it does take more mental energy.
A friend of mine ran sub 4 for the first time in his late 20s with only his girlfriend to time him at the track. Since she was a former runner turned college coach, she was willing to sit in the rain and the cold and the heat and time him doing workouts. His college times were more like 4:10. He did this for about 6 years before it just became too much and he hung it up. He did have an occasional running partner for his tempo and base mileage days, about 1-2x per week.