Is it possible and practical to transfer all of my son's stuff on his Win 10 computer to my win 10 computer without disturbing my stuff?

I have 4TB off SSD, so space is not an issue.

If this isn't possible and practical, maybe I could put his SSD into my computer and dual boot provided I have a free slot?

Or could I set up a Virtual Machine for each of us?

I have a great computer, but I don't need its capabilities anymore. My son could use those capabilities, but I still need my less intensive programs. I'd rather not buy another computer and I don't want to reinstall everything we have.

Just create a User Account/Profile for him on your Windows 10 PC and give him administrative rights so he can install & transfer away.

Transferring data is easy - You can use his SSD (internally or externally) on your PC to move data to the destination machine.

Software will need to be installed on the destination machine though...

We have a 6mbps DSL connection, he has 500GB worth of programs, and I’d like to get this done before we leave in August.

I looked at his computer and he’s got an SSD and an HD. I’m thinking I’ll get an SSD big enough to clone his SSD and HD to, pop that in my computer and use boot manager to pick which SSD to boot from. I can boot to his SSD in safe mode, strip his computer specific drivers, boot back into normal mode and get the drivers for my computer.