I have lots of experience getting out of shape, then back into it, and I'd like to recommend a very simple template that's hard to get wrong and evolves from where you are now.
1. repeat a given mileage for two weeks before increasing it. Runs should be easy. If you can't repeat easily, it was too much. Have a 'down' week in between, or when life is busy.
2. Do two "quality" sessions per week, 3-4 days apart.
(a) consists of either 200s on the flat, or 30-40sec reps up a moderate hill with a smooth gradient, or alternating if you can. Start with 4 reps, then 6, then 8, 10, 12, 15, 20 (breaking into sets if needed). Think about good form and nothing else. No all out sprinting. Either 200 jog rest on 200s, or walk down hill until ready to jog on hills. The recoveries speed up as you get fitter. This way, you will gradually progress from a few strides with long rest, up to a fairly substantial interval session relevant to 3000m.
(b) is some kind of tempo or progression run. Tempo effort, NOT hard, gradually lengthen tempos from 2mi up to 4mi or so (5 when really fit).
That will cover most things and has built-in "control mechanisms".