Best tour company for solo women?

I'm looking to go on a 7-10 scotland tour and hoping for something very structured. I'm nervous about the risk I wont make friends so if there is a lot of free time that could lead to a lot of alone time/ feeling lonely.

Experience with groups that have little free time?

I know people personally that have enjoyed and use g-adventures lots but it looks like there's lots of down time?

I found online the company Trafalgar which may be a little less down time but I have never heard of them before

I am interested in learning about history and culture, not really looking for a party trip but that may end up putting my with an older age group (I'm 30 myself)