This guide assumes that you already have obtained the content legally, RetroArch does not provide users with copyright content.
You should already have both cores and content, now we just have to launch it!
Go back to the Main Menu and select Load content. From the last guide you should have already set the default start directory, if this is the case choose Start directory. If you haven't set it or you are choosing other content (such as downloaded content) select the relevant option.
From here it is up to you to navigate your game folder and find the game you want to try, select it once you have.
If the game is zipped you will be presented with two options. Browse archive will allow you to open it and select the contents. While Load archive will try and load the archive as an image. In most cases if you simply just compressed the image, either option will do.
RetroArch will automatically choose the appropriate core for your content based on file extension. However if two or more cores use the same file extension, it will ask you to choose the core. You should always choose the platform the game was suppose to run on.
Well done, you have finally launched your first game with RetroArch.
If you setup your controller take note of the RetroPad concept. With this you will not have to setup a controller for each console, instead the RetroPad will adapt depending on what console your playing.
To return to RetroArch, press F1 or the RetroArch button on mobile. This will bring up the menu where you can change core settings, or otherwise configure the current content, or close it.
On PC's pressing Esc twice will close RetroArch without saving.