Its all about progression. You aren't ready to train for a 5K or run 40 miles per week. You need to learn correct running form and strengthen your leg muscles.
Goal #1 should be to improve your 400m time. Buy some track spikes and watch some videos on Pose running. Take 2 months and train like a sprinter. Don't worry about endurance, you need speed. Run your hills and intervals as fast as you can without having form breakdown and take full rests. You need to try and get down to at least below 70 seconds in the 400m.
Typical Week:
M - 1mile warm up, 6x100m hill sprints, 2mile cool down
T - 3 miles easy
W - Off
Th - 1m wu, 6x200m on track (full rest between ea.), 2mile cool down
Fri - 3 miles easy
Sat - 5 miles easy (do 20min of plyometric leg exercises afterwards)
Su - Off
Total: 19 miles per week
You can increase the number of hill repeats if the workout starts feeling too easy. You can vary your interval numbers and distances, but don't go over 1600m for a total session and over 400m for any one repeat. (ie. 4x400, 5x300, or ladder 100-200-300-400-300-200-100).
After 2 months of this type training you can move on to training like an 800m runner for 3 months. Goal should probably be 2:30. Intervals will start to total 3000m and mileage total should bump to 25mpw. Every other week should be intervals with full rest, and alternate weeks should be intervals with rest equal to time elapsed during last rep (ie if you run 400m in 90s, then take a 90s break between reps).
Next, You'll train like a mile runner for 4 months. Intervals will bump to 4-5K total. Sat. long run should hit 8 miles and total miles per week will be 30. Interval intensity should drop during this period and rest time between reps should match the time it took to run the last interval. Goal should be to run 5:40 in time trial mile.
After these first 9months are complete you are ready to drop the track workouts for 3months and concentrate on upping your mileage slowly from 30mpw to 50mpw. Continue to do your hill repeats and add in some accelerations twice a week.
You will then be ready to do a traditional training plan.