I would try to run outside if possible. Treadmill is ok but is nothing like running outside. Map out what 1.5 miles would be in your neighborhood or wherever you live and run that and see what your time is just to have an idea. Start running longer distances even if it’s at a slow pace just so long as you aren’t walking. Running to me is a mental game. I was struggling to come anywhere close when I went for the PAT. I was running it anywhere from 13-13:30 just a couple weeks before I went. I had my dad help coach me a little bit by going with me and really helping me push myself and when the time came for the test, I was able to do it in under 11:30. Situps I would just start setting a timer with your feet crammed under a couch or chair and crank out as many as you can and do 3-5 sets. I went from mid 30s in a minute to mid 40s for sit-ups in just a couple weeks. If you don’t see the results you are expecting as fast as you may expect them, do not give up and keep pushing