Custom Maps Help

I've been playing around with Google Maps lately to create custom maps.

I don't like google but have no experience with any other apps and have never tried mapping of any sort before.

I'm trying to create a map layer(s) that has historic sites, stone circles, woodland, cemeteries, UNESCO sites etc. So if I'm traveling I can stop and see them.

I've created my own Google Map using lists of sites from Wikipedia. This has gone ok but leads to a lot of data cleansing and the functionality isn't great.

I've seen this website but it isn't as complete as the Wikipedia text lists ive imported: https://www.hmdb.org/

I'm completely new to this and have no experience. Are there any good resources out there for me to use or contribute to?

I'd like to de-google as much as possible.

P.S. do I need to enable developer mode or root my phone to install open street map now?

Thanks!