I dive almost exclusively solo because most of the other divers are already paired up. My local boat captain and crew all know me and know I have a very simple solo dive plan. They don't kick when they see me setting up my backplate, no bc, double hose rig, Duck Feet fins and steel 72. 99% of the other divers, including the instructors, do however look at me like I have two heads. It's really fun when the conversations get started on the way out to Catalina.
If I am fortunate enough to go for a swim with another, diver, a newbie, I almost always let them plan the dive - it builds confidence and dive character. Plan your dive and dive your plan. I will only add during her or his briefing my experience at this site and certain things that may come up to alter the plan, unexpected currents, heavy kelp, deep over thataway, shallow over there, "the last time I was here" . . . . etc etc.
There are places I won't recommend to new divers - night diving in heavy kelp, offshore platforms with heavy current, shore dives with building surf. Also, if conditions look as if a new diver just won't have fun, ( strong currents, low vis ) - find something else to do. It's not worth getting wet and cold over. No big deal.
When I travel, almost always solo, I really prefer to dive alone depending on the location and conditions - just too many "vacay divers only" - or, ill get to know the DM and we'll dive "kind of" buddied up - especially if she's cute and single (just kidding) well, . . . .
I enjoy having really new divers in a group though, it adds to my enjoyment - I haven't been "new" in 40 years