I would expect a third instalment from Ant Man (and the Wasp), and I'd be somewhat surprised if we didn't get (at least) a Spider-Man Trilogy (although considering how young Tom Holland is, and how big the Spiderverse is), it's quite possible we'll get quite a few films out of the MCU version of this character providing the MCU hype remains strong.
It's obvious the likes of Vision, Wanda, Clint & Natasha aren't going to get any solo films, although there's ongoing talk about an all-female superhero film taking place at some point I'll believe that when I see it).
Black Panther, Doctor Strange and Captain Marvel I remain sceptical about as far as sequels go. Captain Marvel obviously hasn't come out yet, but it depends on what origin story they try to tell, and where they can go afterwards. It's possible that we could get Black Panther sequels, but it'll be hard to match the first if they follow the footsteps of the first (primarily with it being set in Africa/Wakanda and about the throne).
Doctor Strange I see as more a supporting character now; in that he'll step in with the Avengers, or make cameo appearances in other films. I just think Cumberbatch is quite busy, so scheduling him for a full solo film might be tricky. I guess it depends on what other characters they can throw into the MCU too.
Then there's characters we've not been introduced too yet; I'll be amazed if we don't actually get a cameo from the F4 in either Avengers 3 or Avengers 4, now that they belong to Disney/Marvel again. There's got to be a trilogy for them, easily.