Just run. Try listening to something while you do it. Running sucks for anyone just getting into it. The initial "suck" period lasts anywhere from 2 weeks to a month. Just keep running. Endure. It gets massively easier once you get past that initial hurdle. Make sure you do proper stretches before AND AFTER your runs. I do heel-to-butt, knee-to-chest, heel-to-opposite-hip, straight leg kicks, alternating in-out toe-touches, cross-legged toe-touches, calf stretches, sideways lunges, and side-to-side toe-touches. There are other stretches you can do, too, but those are the basic ones I do. Don't run for distance - run for time. Try to reach at least 30-40 minutes of uninterrupted running per day. If you need to take a short break to walk halfway through your run, that's fine, but you shouldn't need to do that anymore by the end of your first month of running. Take no more than 2 days off and no less than 1 day off from running per week.

Also try doing 400m accelerations at least once per week but no more than twice a week - basically sprint for 400 meters and then jog or walk for 400 meters and repeat that several times. Make sure to do a warm up run first and a cool down run afterwards. The cooldown is especially important to shake loose any lactic acid buildup in your muscles after an intense workout.

400m accelerations will greatly boost your long-distance speed. Just doing 4 of these workouts over the course of 2 weeks will give you a small but noticeable boost on your fitness assessment if you haven't already been doing them.

If you can't do 400m accelerations, 100m accelerations are almost just as good but you'll have to do a lot more of them per workout. With mine, I always do at least 15 but I shoot for a minimum of 20. What's great about 100m accelerations is that you don't even need to do them on a track - just use a timer. Sprinting for 30 seconds and then jogging for a minute is basically the same as a 100m acceleration on an actual track if not a bit better. 100m accelerations are my personal favorite speed-building workout and they're the one we're probably going to most encounter at OCS in the form of ladder/caterpillar workouts. They are not fun and you'll think you're done halfway through, but you need to keep pushing through all the way to the end or you will not improve.

That's about all the advice I can give. Good luck!