ZANDATSU

Hey all, I am new to Emulation and I have trouble running Neo Geo on my Retroarch/Launchbox.. It says missing cores even though I downloaded ETA PRIME's recommended core (FB ALPHA.) .. any advice will help, is it my retroarch emulator maybe? it looks kinda funny I did add the roms in the rom folders & added the bios with it. I also pressed enter already to add the cores needed. However with all that added , it still does not play the games. I used FB Neo. What am I doing wrong?