Open world game

So i am more of a modelling guy, with some experience with programming. I want to model a map for a survival game which we will be doing as school project, so i want to ask should i just model a map in one scene? Or should i use level streaming (like each city for it self etc?) or what would you suggest? Game will definitly use multiplayer as we need to include MP based on project description.

That’s a really bad idea to do without much experience, it takes a lot of work and experience to do open world stuff.