Welcome to the Recalbox documentation, hopefully you'll find what you are looking for, depending on your needs, here's some suggestions :
We suggest you to look the page about Installing Recalbox, you might also want to check out the Manual to understand the basics on how the operating system works, if some words are too technical, the Glossary might be of help too.
We have some lists about compatibility, the Board compatibility page describes the various versions of recalbox you can download, along with supported emulators, if you have an actual computer, we recommand seeking the PC Compatibility documentation.
Also, the Peripheral Compatibility page lists some tested peripherals, which might be useful, keep in mind those lists may not be exhausive.
Recalbox is a free project, as such, people work on it on their free time, which means it may have some bugs or may not be as "plug and play" as a full fledge commercial product, so the best advice we can tell is to be curious, read the documentation, and back up things before doing anything you might not be sure about.