Honestly, I would do as many as you want. I have my first solo trip planned/booked for the end of August for 5 days. I am booking lots of dining reservations (deluxe dining). I have never dined solo at WDW so this will be a new experience. Hopefully, I won't be uncomfortable. I am reminding myself this is an expensive trip and why wouldn't I eat where I want. People don't know if I am travelling with someone and that person wasn't able to eat with me at that particular meal.
I don't have any character meals planned. This isn't a priority for me but if I saw a character I wanted a photo with and there wasn't a long line, I may do it. I'm planning on attending
MNSSHP and there sounds like a lot of photo opportunities. But, I don't think I'd stand in line for a long time (personal choice).