Warning! The following contains spoilers for Avengers: Infinity War and Ant-Man and the Wasp.
One of the huge benefits of Spider-Man being in the MCU is that he gets to interact and team up with other Marvel heroes, just like in the comics. This possibility paid off right away in Spider-Man's first solo MCU outing, Spider-Man: Homecoming, when Iron Man provided some crucial assistance to an out-of-his-depth Peter Parker. With the sequel film, Spider-Man: Far From Home set to begin production soon, it's time to start speculating about what other Marvel heroes Spidey could cross paths or team up with during his sophomore film.
It is worth noting that a lot MCU heroes are currently dust in the wind after Thanos' snap in Avengers: Infinity War, including Peter Parker. But given the very existence of this film, I think it's safe to say that will change somehow. So for the purposes of this exercise, all of the MCU heroes are on the table, as well as some possible newcomers, the only exceptions being Iron Man and Doctor Strange, and neither will probably be in the movie.
Spider-Man has a long history of teaming up with heroes across the Marvel universe in the comics, so let's make some guesses about which Marvel heroes could team up with the web crawler for his abroad adventure in Spider-Man: Far From Home.
We know that Robert Downey Jr. will not be returning for Spider-Man's second MCU film, but that doesn't mean that Tony Stark doesn't still want to keep an eye on his young protégé. Regardless of Iron Man's eventual fate, he has a vested interest in Spider-Man and there are probably few people he would trust more to look out for Peter Parker than James Rhodes. War Machine may be a little too similar to Iron Man to be novel from a visual or combat standpoint, but from a story perspective it would make sense that Rhodey would be looking out for Spidey and have to team-up with him when villainy takes place.
Peter Parker and Scott Lang (along with Hawkeye) are unique in the MCU in that they maintain the most normal lives among their heroic brethren. Peter still goes to school and has girl problems while Scott just wants to be a great dad to his daughter. They also have the most aww shucks, fanboy approach to the hero business. I could totally see each geeking out over the other's skills in a really fun way. I would love to see these two team up somehow. Without knowing the story of Far From Home, and Ant-Man's current Quantum Realm predicament, it's difficult to say exactly how they would cross paths; still, I'm sure Marvel could make it work. Tom Holland has even advocated having Spider-Man team up with Ant-Man next and he already has some ideas about what that could look like.