sheldon brown’s site has some articles for beginners and for repairs, I feel like a basic maintenance article should be there somewhere or on a search engine: https://www.sheldonbrown.com/beginners.html
the scope of “basic” to me feels like it expands at times, but if you read around you can probably find different ideas
rope and tree branch?
I like the idea better than races but don’t really like timed riding or events but instead like the unracer meme of going out to “just ride”