I’ve sailed solo on Celebrity, RCL, NCL, HAL, Carnival and Princess. IME most cruise lines have one lunch or solo meetup during cruise sea day but not much more unless NCL. NCL has solo studios (inside and usually higher priced than inside or oceanview). If you sail solo you can participate in activities and lounge happy hours and shared dinner table even if not staying in studio cabins. I’ve sailed NCL transatlantic so lots of folks solo and things to do. I met new friends on NCL.
As for food, I have food allergies so all lines catered to that.
I sailed Celebrity Edge which has solo verandah rooms and loved newer ship. There was one lunch meetup but otherwise I was on my own. Joined a few tours but folks weren’t keen on chatting. I love Celebrity bc more luxury touches but less activities than others.
i write philatravelgirl blog which has some solo posts
hope this helps
