collaborative editing and displaying a map

I would propose something completely different than the other answers: please give a rough indication of where your community is and what it is about.

I would suspect that an in person introduction to OSM would tend to make much more sense for your community than simply dumping something on them. A knowledgeable OSMer can interactively, in discussion with your community, work out what the best way to particpate in OSM is. Or put differently: I don't think that concentrating on technical solutions to partiopation makes any sense at such an early stage.

Probably UMap where you can scribble onto an OSM basemap. Viewable in any browser; "collaborative" editing in the "whoever has the link can edit" sense (i.e. no recorded history).

Long-term we'd of course like to recruit you and your non-technical community to OSM where at least those objects that are of interest to a larger community can be added directly into our database, instead of just scribbled on top.

If the additions are appropriate for OpenStreetMap(OSM), then please help by improving the shared map. As in they are real objects, and people are happy with the additions being public (may not be the case if it is on private land). This would include paths, woodland areas, and maybe individual trees. There are a number of guides available such as the OSM Wiki and the Learn OSM website.

If there are existing OpenStreetMap volunteers in your area you could see if they are running any events you and the community could join, or if they could you run a workshop for the community.

For items that are not appropriate to add to the OpenStreetMap database then I recommend uMap by the French OSM community. You can draw points, lines, and areas on top of an OpenStreetMap layer and keep that map or share it with others, but it keeps this separate and does not save it into the OpenStreetMap database.