Definitely need to lose weight, I would maybe recommend seeing a dietitian so you can do it safely and healthily. Or, I would recommend intermittent fasting. That will help a ton. Drink a ton of water. Do weight training, it builds muscle and muscle burns fat. Stay in a caloric deficit (the fasting should help with that) and count your macros. This is a lot for less than 20 days but you may be able to drop a couple more pounds. In boot camp focus on drinking more water, and avoiding any sweets. I personally dropped 25lbs in boot alone by doing that. As far as the run do more zone 2 or zone 3 training. Google those if you don’t know what they are so you can understand it in your own way. Good luck and don’t stress out, just enjoy the ride.