There's a lot of links in this prior thread. Probably too many, so let me call out...
- Everything here, and especially the lifetimes misconceptions once you start struggling with lifetimes
- Interprocedural conflicts plus the last the Baby Steps links here, under "ownership and shared mutability"
Those are mostly more article-esque than technical deep-dives. If you find yourself more puzzled than enlightened, just ignore it for now and revisit later.