Hi Eddie! We’d love to hear your stuff and anyone is of course welcome to submit as everything here is for free anyway.
As Marco said, there are some fairly easy guidelines to help you out in figuring out how or what you want to contribute, but most of us deviate from this just a little bit for different various reasons.
That said if you are going to formally submit something, preferably it should be a sampler instrument that uses a common format, such as Kontakt, EXS, sfz, or ableton sampler, and include the audio samples as individual files too (Not samples baked into the format like Kontakt monolith or sf2). A story or some pictures about your creation would be awesome too!
If you’re still not sure we would love to help you out with more specific questions on the forum!