Just You is a company for "single travellers" rather than single people.
I have found that the majority of people on a tour are travelling by themselves (whether single in life, widowed, divorced or separated).
However, there can be people who are friends who want to travel together but don't want to share a room; or people who have met on previous tours and formed a holiday friendship, they find they have another destination in common and book for the same tour; and sometimes there are people who have a partner at home who can't or won't travel to the destination their other half wants to visit. Just You makes travelling solo a possibility for everyone.
Do be assured though that JY isn't for couples travelling together!
As a Tour Manager who has led both Just You and Travelsphere tours, I have found that usually the guests on the tours mix very well. Some people are very confident from day one but for others it can take a day or two relax, this is only natural if you are taking a holiday by yourself.
As the TM we have a responsibility to ensure no one feels isolated, but as travellers on the holiday everyone has to make the effort to introduce themselves to their travel companions and socialise with the others.
Whether it is a short break in Europe or a 3-week long-haul tour the thing everyone has in common is the desire to travel to that specific holiday destination and a sense of adventure to experience the different cultures, cuisines and traditions.
JY has many repeat travellers because of the great experiences people have, so from time to time, just by chance, guests meet someone whom they met on a previous tour.
If it's your very first holiday on your own, I'm sure you'll find a sociable crowd who are looking forward to the wonders of travel as much as you are.