Can i put GBA roms and retro roms on my edge card

I have just bought a nintendo ds and have ordered an Edge Card so i am fairly new to this whole process. I understand how to do the nds roms but I was wondering whether it is possible that i can put GBA and or Retro roms on to my edge card and play them via my nintendo ds, is this possible?

Retro roms would require an emulator on the card, so if you can run homebrew and can find a suitable emulator then you should be able to run retro roms.
The edge is a slot 1 flashcart, which means it cannot play GBA roms.

where can i find a suitable emulator and how would i transfer it to the edge card

You could google it, the emulator normally is just a .nds file, just like a normal NDS rom

Check out my Emulators for DS topic :) https://www.romulation.org/forum/index.php/topic,5002.0.html The emulator has to be .nds, or else it can't run, unless it is packed into a format one or two firmwares can read from and unpack.

Thanks i will use thse emulators as soon as i can get my edg card working

so if i put one of these emulators on my ds, the goombacolour, and then put GBC/GB games on with it will I be able to play them?

Lameboy, yes.