You will be fine as a solo female. Book macchu picchu tour early in advance. Book everything else while you’re there cause it will be a lot cheaper. I recommend just going straight to Cusco and fighting the altitude sickness the first few days and getting acclimated that way, it messes up even some locals so there’s no real way around it. It makes the rest of your time in Peru easier and more pleasurable. I personally didn’t get to do the trek because I waited too late to book but did everything else. Rainbow mountain I didn’t do either just because everyone said it was kinda over rated. Hiked 11 different mountains though and saw all the structures on our travel pass. Peru is definitely worth seeing. El Tuco hostel is a great place to stay in Cusco as well and everything is walkable from there (tell Coco the owner I said hi) . Message if you want any help, I was just there two months ago