Backstory: I recently started DMing a D&D 5e campaign with my college friends. It is my first time DMing and most of their first exposure into DnD. They are all video game players so they are all very knowledgeable about the material.
Problem: I just finished running the second night of our beginner campaign using "The Lost Mines of Phandelver" from the Starter Set. Our first night was longer as players got used to combat and I got used to DMing certain things (checks, rules, etc.). Our second night went great, a total of 15 goblins, 1 bugbear, 1 wolf... SLAIN!
We have a very large party (6 members) as I tried to be inclusive to my friend group and give everyone a shot who wanted one. Combat at lower levels and "dungeon crawling" can be a bit of a slog and boring. Some of the players were involved and coming up with inventive things all night (WOOOO!).
A few members seemed almost to not care and were multitasking another game most of the evening (we play online using Roll 20).
How should I handle talking to these members to see if they really want to play, or if they were just curious and aren't feeling it?
I suspect they are still playing to feel included with the friend group and would feel left out if 1 night a week they weren't "playing" with everyone else, but I still think they just aren't enjoying it.
TLDR: How do you handle players that don't seem interested? Do you talk to them 1 on 1 and see if they want to stop, try and find ways to involve their specific PC skills, etc.?