4.26, issues I'm having, Yes I'm freakin new and frustrated

the way to do something without frustration is to take each thing separately and try to solve it.
you talk about 5 different things and its confusing for anyone to pinpoint what your problem is. I’m guessing its confusing for you as well.
so, trying to unclutter that mess, i conclude that the issue is that ue crashes when you do an import of a tiled landscape.
first of all, dx12 and visual studio and WM license have nothing to do with importing a tiled landscape.
now assuming you did all the pre-steps properly (creating a blank project, new map, enabling world comp, etc) and assuming you’ve read “hours” of documentation you should be good to go.
but what is this “world machine a Y23, X17 windows”?
have you tried importing just 2x2 terrain?
do you have enough space on the drive where ue is installed? apart from memory, ue saves those tiles as individual maps on your hdd.

the virtual memory error is weird, i’ll give you that but it might actually be an issue there. do you have issues with other 3d apps?

finally, when i had issues with tiled worlds these were very helpful: