There honestly isn't much I can say here is that PT is a way of life for the Marine. The most important thing about PT is to do your best and give 100%. If you fall out of a run, accept the chit and improve yourself. If someone yells at you for doing something wrong, just fix it and don't let it get to you. You will be so active at OCS that it is not necessary to run on liberty. I would REST. However, keep up your pull-ups 3-4 times a week on your own, even if it's just some sub sets before and after lights. I did crunches and pull-ups after lights.
Be careful out there! In the winter, the mud will freeze and thaw. Muddy footprints turn into jagged terrain when it freezes. Be careful not to roll your ankle.
After lights, you can use BioFreeze and ask fire watch for ice. Don't fall asleep with the ice bag...
Use your foam roller, especially if you are skipping stretch PT to do obstacle course remediation. Go to at least one stretch PT in order to learn some good stretches and how to use the roll properly.
If you are injured, you can sign up to go to physical therapy or medical. If they find something severe enough, you can get dropped. I was terrified of this and hid my broken foot for weeks. I'm glad I made it through OCS, but I could have really hurt myself and given myself a lasting disability. I broke my heel and had eight stress fractures in my foot and lower leg. The doctor told me that if my heel had broken worse, I could have been walking on screws the rest of my life. No bueno.
Trim your toenails short. I did this and still lost two toenails at the end. They grew back, but this was at the end. Other people lost them mid-way through.
In the fleet, females can PT in ponytails. At OCS, we still had to wear buns.
I believe you can wear ankle braces, but verify with medical in case I'm wrong.
Before PT events, you can go to ATR (athletic training room) and get your ankles taped. Some people did this all the time. I got my ankles taped before a hike. I hated it and was lucky the hike was delayed an hour. I ripped them off before the start. Do NOT use a brace and tape together, unless ATR says you can.
Get a decent pair of running shoes. At OCS, your feet will swell a half size. If you notice your sneakers are getting too tight, invest in a pair a half size bigger.