it’s possible to do this, yes, but you really should make sure whatever you download is licensed in a way that permits your particular use cases. iNaturalist observations have a license, and the their media assets (photos, sounds, etc.) have separate licenses.
i’m not sure how big your particular project or how it’s defined, but if you’re dealing with a very large set of observations, i would probably turn first to the AWS Open Data set to get photos / images: https://registry.opendata.aws/inaturalist-open-data/.
for fewer than 10,000 observations, you could start with the iNaturalist API: https://api.inaturalist.org/.
hopefully that gets you started. if you need more help, you’ll need to provide more information on exactly what you’re trying to do. (which project are you dealing with?)