Can't be bothered to go back and check if last month's me had a different opinion but looking at the squad I think a CB, CM and RW are absolute musts. After that a striker and either a 2nd CB or 2nd CM, depending on departures. I'd list striker among the priorities if I knew what's going to happen with Rooney.
Don't watch a lot of continental football so most of these suggestions are based on what I've read about our supposed targets in the media and seen on youtube.
CB: Varane/Marquinhos/Manolas/Koulibaly. Don't have much of an opinion here, just as long as we don't blow 50m on Stones.
CM: It's kind of amazing to think we're still lacking so many attributes in CM after signing 5 CM's post Fergie. Energy, pace, drive, pressing ability in someone like Sanches or Kante or creation from someone like Kroos or Gomes? Ideally we'd get both, but I think passing and creation are more important here.
RW: I like the look of Joao Mario here. CM turned RW, seems to be creative enough and would give the side defensive balance while allowing Martial more freedom to focus on attack from LW. Would also allow us to seamlessly switch between 4231 and 433, or even playing some kind of 4231/433 hybrid system with a left footer placed nominally on the right, but drifting centrally and doing most of his attacking work there. Could be the player that allows us to sign Griezmann and play 433 without really having to play him out of position.
Striker/forward: Not sure what we should be looking for here. I'd like to see Martial move up top eventually, and then there's Rashford's development to consider as well. Zlatan or Higuain maybe. Or someone younger, with a lesser profile that won't expect to be an automatic starter like Lacazette/Janssen. Don't want us to blow our load on Lukaku, I'm not at all convinced by him and he'll cost an absolute bomb. Same kind of goes for Aubameyang, not sure he's anywhere near worth ~world record money.
5th signing: Either a 2nd CB or CM. With Jones permacrocked and showing very little progress, Rojo being a sunday league footballer at best and our young CB's not quite ready to be 3rd/4th choice, I think a 2nd CB is a more pressing need.