Look up Daijisho on the play store. It's a front end that will organize all your roms and emulators. You probably don't want to rely on touch controls, so depending on your preferences you could get something like a gamesir controller which your phone will fit into, or use an external controller.
This video is a good guide for setting up Android, and this one for setting up Daijisho. They're both very exhaustive guides, his videos and website are excellent resources for anything emulation.