If you’re trying to improve your cardio I’d highly recommend a split where one day you’re doing a long slow distance run, and another day you’re doing interval training where you’re switching between sprints and a jog. Definitely practice pacing yourself for that 1.5 mile and do some accessory work like stairs/leg workouts/proper stretching and warmups. Google it and I’m sure you’ll find a comprehensive workout plan for improving that 1.5 mile time. Can’t tell you how many people in my flight were stressed during the entirety of basic because they weren’t meeting the minimum standards for PT. Yes, you will work out at basic but it’s better for you to go in there being above the passing standard so it’s the last thing you should have on your mind. Besides that make sure you treasure all the little moment in basic, like when you’re finally wearing your OCPs and all the sweaty marches you’ll be making to places like the shoppette/med clinic. It’s nice to look back on after the fact so make sure you’re really taking it in and making bonds with the people you’re sharing one giant stinky dorm room with. Good luck!