So I can't play any of these games on my smartphone that is a computer?

No, wrong type of processor. Yes it is powerful enough for a lot of games but no, they cannot run without being translated for that type of processor first. GOG does not sell anything but games compatible with the x86 architecture.

I have read there is a version of DOSBox for Android so you can get DOS games to run on your mobile.

Unless the thing runs a desktop version of Windows, macOS or Linux, 'fraid not.
EDIT: Try Humble Store: they have some games that include Android versions (find the "Platform" filter & select "Android").

Some of the adventure games sold here work with ScummVM, but you'd have to be able to extract the needed files from the installers. (Or install to a computer with a desktop OS and copy the files over.)

Thank you! I was just trying to play Emperor:rise of the middle kingdom and it let me download the game to my phone I wasn't sure if there was a way I could get it to work

let me download the game to my phone I wasn't sure if there was a way I could get it to work