Ah. Any issues at all before the upgrade?
I would probably grab any necessary drivers, save them to a USB, and do a fresh install of W10. Without any rhyme or reason to the crashes, it's often better to just start over rather than ripping your hair out trying to figure out what is causing the crash.
2/3 upgrades I did went smoothly; the other couldn't stand the graphics drivers that W10 kept insisting on downloading and would crash to a black screen entirely shortly after booting.
There is a "media creation tool" you can download from Microsoft that will let you make a USB or bootable DVD to load W10 from.