I don't know about any newbie friendly resources, would be interested in that as well. I guess most datahoarders are also selfhosters, so I'd to look into that as well. Start small, get a smalll cheap, used computer, maybe with an external drive. Check out some docker(-compose) tutorials.
As for data corruption this is something I thought about recently as well. I have not seen a good solution, someone said ZFS with redundancy will autocorrect bitrot. Not sure if this is even possible (or practical) on a computer (can you have the redundancy in another pool partition?)
Would https://umap.openstreetmap.fr/en/ work for you? It's Osm plus markers etc(?) you can put on top of it. Not sure if you can make it work offline/selfhosted. I used it for marking interesting locations in a city some friends wanted to visit that I know quite well.
Lol.