Well for the GBC all you need to do is to drag n drop the roms into the rom folder of GBC.
As for MAME. Well, you need to know which emulator you're going to use and you need that romset, lets say the romset is something like the version of the roms.
I can recommend you to use the lr-fbalpha emulator, this requires the 0.175 romset. if you can find this romset and download the games you're fine, all you have to do then is drag n drop the mame roms to the FBA roms folder and you're ready.
However, if you find a different romset you need to "upgrade" this romset to the romset the emulator is supporting. You can do this with a program named clrmamepro.
Here is how I did it the quickest way, just check this page:
https://github.com/retropie/retropie-setup/wiki/Managing-ROMs
See which romset is needed for the emulator you're going to use, like for an example "fba 0.2.97.39" Just add the two magic words one starts with a "D" and the second starts with a "R". Use Google for this. There is one site it's name starts with an "A" and ends on ".org". Well I said to much now... Good luck!