Hello, Oddonelynx! Preset reference files can be found in C:\Feralheart\my_presets\references. There are also other versions available on sites such as
DeviantART. I recommend making copies if you plan to use them so you do not accidentally overwrite the original file. As for making presets, like Esarosa said, there are plenty of tutorials avaliable on the forum and other websites. Only after you export the preset can you upload it to the preset sync for others to see.
If you need specific individual help regarding presets, I would be happy to help you and message your screenshots or even make a video explaining the process if necessary. If you need any other resources for preset making, feel free to ask.