Well this will be interesting, I get:
I think I'd actually do fairly well. As for weapons/vehicles Wedge would get his X-Wing, Spiderman (assuming he comes with his suit and web blaster) would choose a warmachine suit for support, and Diddy and Dixie would get Rambi the Rhino. As for the Stranger Things characters I'd probably give them some sort of melee weapon, aside from Hopper who would get a gun. I feel like he would be the only one able to more consistently get headshots.
The week would be spent having Peter build web traps and defenses, Wedge teaching survival and defensive tactics, and building a long term plan. The X-Wing could also be used to gather supplies quickly.
When the zombies attack I think they could hold off for a while. The warmachine suit and Wedge could thin crowds pretty quickly on their own. Diddy, Dixie and Rambi would also be effective at taking out some zombies since they should be slow enough that they wouldn't be able to grab onto Rambi while he is charging. Spiderman (Homecoming) would probably be most effective at crowd control, using his webs to block or redirect the herd of zombies. Other than Eleven most of the Stranger Things cast is weak, but they aren't all stupid and their plot armour should help them survive for a while. If the X-Wing and warmachine suit can be rearmed and refueled then I think my team would do fairly well. If they can't, then it is hard to say, all depends on how many zombies there are.