This is week one. I am in Leh right now. Below advice applies to all. Your specific plans will follow shortly.
The main thing to do right now is focus on strength training. Some basic ones shown below.
Besides that simply do time on feet for now. No running. Just move 4-5 times a week. 30-60 min a day. Trust me, we'll get to the finish line, smiling.
If running is your love, strength training is your mother-in-law. Get the basics right by doing the exercises below. The rest will follow.