You must press F1 while you’re in the ES-MAIN-Menu, otherwise the menus for CEMU and RPCS3 won’t open.
After copiing your PS3 roms in your …/roms/ps3 folder you have to open RPCS3 and start first game launch from here for pre-compiling every game first, later on you can start as usual directly from ES-menu
Wii u: try to get “Loadiine”-files instead of wux and wud files for these will probably not work due to “key-error” message. unpack loadiine (rar) and copy folder (code/content/meta) in …/roms/wiiu. after that open CEMU by pressing F1 in ES-main-Menu, select path to your wiiu-roms-folder and you are done. copy all rom-updates and DLCs in a new folder (e.g. …/roms/wiiuupdates) and install by selecting “install Game, Update or DLC” from CEMU menu.