Booking tours in advance as a solo traveller? (Cusco, Peru)

Next week I’m flying to Peru and I’ll be spending the majority of my trip in Cusco. I’ve already booked the Salkantay trek but I also want to visit the Manu rainforest, preferably for 6 days. Unfortunately since I’ve already booked the trek and a bus ticket to Huaraz at the end of my trip, my dates are no longer that flexible so the rainforest tour pretty much has to start on the 2nd or 3rd of August .

I’ve been in touch with multiple tour agencies but since I’m a solo traveller it’s not possible for me to book a tour unless they already have other bookings for the same date . How do you deal with this stuff while traveling solo?

I’m pretty new to solo traveling and this is my first backpacking trip so I’d love to hear your views on this. Would you advice me to wait until I’m in Cusco? Is it possible to find decent tours last minute? The rest of the activities I’ve got planned, day trips and such, are not something I’ll be booking in advance but I feel like visiting the rainforest is so important to me and I’m worried that if I don’t have a set date for it already then maybe I’ll end up missing out on it.

Booking tours in advance as a solo traveller? (Cusco, Peru)