I am gonna put down a theory of mine about the next movie after seeing the film yesterday.
I found it interesting that the only members of the Avengers that weren't killed were the original ones (Iron-Man, Captain America, Hulk, Thor, Black Widow, and I assume Hawkeye even though he wasn't shown in the film at all as far as I remember). The only exception to this is Rocket but he was the only Guardian left alive. I don't really think he was an Avenger. I feel like the next movie will be the original members fighting against Thanos to get the gauntlet and bring everyone back. I think this was the only outcome that Strange saw that resulted in them winning which is why he gave up the Time Stone even though he told Tony that he would let any of them die to protect it.
My mom also pointed out that the Hulk may know something which is why he's not coming out anymore. This seems like a stretch though because I just feel like he's being stubborn and doesn't want to come out because he got his ass whopped and is now scared of Thanos.