If you are not used to structured training, I would recommend starting with Core and General Strength workouts 2x a week, Zone 2 runs/hikes 2x a week and a longer Zone 2 hike on hilly terrain. Gradually increase volume by 5-10% each week.
Maybe four weeks into the training, you can do Max Strength, Weighted hill hikes (10%-20% of BW) and Muscular Endurance (ME) workout. For ME, start with a weight high enough that your legs are the limiting factor and not your breathing. Check this article for more information on ME –
Vertical Beast Mode: What Is Muscular Endurance? Why Is It Important and How Do You Train It?
You can skip the ME workout in the recovery week.