Freshman looking for tips on how to model base phase.

Train like a 10k runner to improve your aerobic endurance. Times across the board will drop significantly.

Don't go nuts with increasing mileage, rather increase slightly but keep solid, strength-based workouts (1k reps, mile reps, tempo runs, all relaxed and no straining). Extend the long run but keep them relaxed, you are not a half/marathoner, it's not the most important session for you.

Build up to running a hour or so once a day. Once a week try to do a longer run in the 90+ minute range. Do some strides or short hill sprints 2-3x a week. 1-2 x a week do a fartlek session. And start your easy runs out super easy/slow, and if you're feeling really good slowly increase the pace and if you're feeling fantastic push it the last few miles into a uptempo run. And try to throw in doubles a few times a week, just 15-30 minutes here and there super easy.

I agree with LateRunnerPhil. Get your mileage up a bit without going crazy and work on strength.

Here's a decent template that I like to work based on

M: Longish easy run on feel (1-2 miles more than a usual easy run)

T: Easy Run

W: Threshold Workout with some fast reps after (4x200)

T: Easy Run

F: Easy Run

S: Long Run

S: Off or cross train

I alternate between 20 minute tempo runs and 7x1200 with jogging recovery. Doubles when I feel like it, except that I always double when I do a 20 minute tempo to get the mileage up. Long runs are 20-25% of my weekly mileage (12-14). Base training is not the time to go crazy and burn yourself out.

If you get your mileage consistently in the 60-70mpw range with maybe a peak week or two at 75 with regular strength workouts you should be in good shape to run a fast 5k.

As a current collegiate runner, I suggest first taking some down time. Whether that is 1-2 weeks off or running every other day for a few weeks, your body and mind will thank you. The collegiate running season is long with no real breaks. Now is the time...especially with the extra time to for a base.

Like other posters have said, train like a 10k runner and focus on getting in some good, solid runs/mileage. Workouts as early as now (Late March. Early April) aren't necessary, since your important races aren't until October/November. Work on building mileage until at least June. Then start to throw in some easy tempos or light Fartleks. You mention your coach will be giving you training in June.

Besides training, pay attention to the little things outside of run training. Getting at least 8hrs of sleep a night and not stay up late over the summer will help you get closer to your goal. Fueling properly will go a long ways as well.

Incorporate some strength training/core. Your coach should give you some in June, but until then do some yourself.

Good luck on your base phase and achieving your goals!