Flat Map Warp

I was wondering if anyone knows any good tutorials, or would explain to me how I could possibly go about this.

I’m looking to make a 2D Flat map, where Player A sails North and reaches the edge of the map. Once there, he crosses it and he’s now on the South end of the map.
Also wondering how that works, for example say Player A is near the edge of the map on the North side. Would he still see Player B, who’s on the South side edge of the map?
I know that I’d have to create a Torus for this but really unsure how, and have yet to find anything that’s helped me in what I’m trying to achieve.