You and find many travellers on Tripoto amd and connect with them. Later you can plan and visit. Jst an example or else book any package definitely there will be many solo travellers.. Meet them make them ur friend and enjoy.
Many travel companies arrange treks and trips. Also, if you want to explore with different strangers at different places, do backpacking and stay at hostels like Zostel, Moustache, gostops, hosteller etc so you can get new company at every place you go.