Looking for ROM-Seeking Advice

Hey there! I’m looking to start getting into emulating games I haven’t played in a long while and sadly don’t have the original hardware for anymore, and wanted to start with a copy of the Mega Man: Star Force games after realizing CAPCOM hasn’t included them in their Battle Network collections. The only trouble is with me being so new to this, I have no idea what places would be good to get the ROMs for, and even if they’d be playable through DeSmuME over Steam’s RetroARCH… If anyone could help point me in the right direction, that would be VERY much appreciated!