Starting out.
 

Hi folks, I’m 15M and I’m trying to get into road cycling and do some races. I’m a track runner primarily but after a pretty severe back injury I’m planning on cross training a lot, so I decided to get a new bike (nothing fancy but my old bike was barely usable). I’m trying to get fit for some road races, but I don’t know really where to start. I biked 22 miles today and felt good but a track runner doesn’t just run 1 mile all out everyday, there’s variation, so I come here. What should I be doing week by week?

If you're really that much of a beginner, don't worry about it too much and don't try to even prepare yourself for races until you've got several thousand miles done. Otherwise you'll just be a danger to the other riders and yourself.

Standard advice -(A) ride frequently, varying the ride length, intensity, and route. (B) Don't try to increase your mileage by more than 10% each week. (C) Enjoy yourself.

sounds good :)

oh yeah - once you've got some miles under your belt, find a group to ride with. You can't race until you've got experience riding in groups.

Listen to your body about fit, especially with a back injury. As your mileage increases, you will experience some pains that aren't just sore muscles, and you need to pay attention to them. I know that athletes, especially young ones, are often encouraged to 'push through the pain', but it's important to pay attention to what kind of pain it is.

For example, when I started riding, I built up to riding 30 miles at a time (I was coming off a decade of laziness), and I started to experience numbness where you don't want numbness. I shopped around and found a saddle that didn't do that. As I went farther and farther, and started doing more hills, I started to get minor pains in my knees, on rides over 50 miles, and the bike felt unstable over 35 mph on downhills. I got a fitting at a local bike shop which raised my saddle and moved it forward, while lowering my bars, all by about 1cm. After a ride or two getting used to it, I found I was spinning easier, climbing with no pain, and the bike descended like it was on rails.

Once you're fit enough, you should be able to ride for hour after hour and not experience pain or numbness, and limited only by your legs.

There is some good information in the racer's forum. The BikeForums.net workout recipe book - Bike Forums

New to Racing? Here's a tip or two - Bike Forums

I raced as a teen, eventually at the state and then national level. First off, there is a subforum dedicated to junior racing. Maybe repost your question there. It will receive fewer answers, but they will be from people who actually are involved in junior racing.
https://www.bikeforums.net/juniors-r...l-disciplines/

See if there is a club nearby with a racing team, preferably a junior racing team. Join them and talk to a coach about a training plan.

The first race will probably be a shocker in intensity. Don't feel bad if you get spit out the back no matter how in shape you are. Finding a fast paced group ride will help, but it's still not the same, especially if your first race is a criterium.

Start by entering the junior category only. The packs are smaller and less daunting. Once you gain pack experience, you can start doing the adult races in your racing category as well as the junior races.

You may even want to see if there is a program at the Kissena Velodrome. It's a great place to learn skills, meet racers, get info, etc. My quick search just comes up with outdated information, but maybe you'll be more lucky.

Eh, not if you start in the juniors category. At the local level, most of the packs I remember being in were 5 to 15 riders. Even at the nationals most classes had fewer than 30. A teen would do well to start in the juniors category and avoid the "Crash 5" crowd for a while.