First, look in the manual and find a copyright for it. That will give you an approximate age of the manual and thus the camera.
It's not cited anywhere as one of the first digital cameras, nor even one of the first commercially available digital cameras. At 1 full megapixel, that puts it quite a bit further along the timeline than the first digital cameras as well.
In comparison, my first digital camera was only .8 megapixels (point eight), and it was nowhere near one of the first either. In fact, I think it was about the 3rd version in that line, and the first of that line wasn't anywhere near the "first" or even "one of the first" digital cameras either. It came out in the fall of 1998 and I bought it for myself for Christmas that year.
A full 10 years earlier than that, the Canon RC-250 came out in 1988. According to the digital camera histories one can find online, it actually is credited as one of the first digital cameras commercially available, though also not THE first. As a camera collector, I tracked one down and acquired it many years ago, complete with it's own unique little floppy disc and charger, still working.
BUT even that is more than 10 years after the very first digital camera that holds the title, which is the Kodak in the story linked here:
Digital Photography The Power of Pixels - IEEE Spectrum
Where to sell it? Probably
ebay. How much it's worth? No idea, but I suspect not much. I would say set up an auction. Start the bidding at 1 penny to attract potential buyers. Set the lowest actual sell price you'll take to something stupid high and run it for a month, and see how high you can get the bidding on it. That'll tell you what the potential is. At the end of the run, if the highest bid price is acceptable to you, even if it doesn't meet the sell price to put on it, you can offer it to the highest bidder anyway.