I've grown mine out over the last two or so years. It's shoulder length now (started at basically a buzz cut). For reference, my hair is straight and moderately thick, so my advice will be directed at someone with hair like mine. My parents never taught me hair care, but my partner has been gracious enough to teach me what they know.

Buy a brush. I recommend one like this. The flexibility of where the bristles connect to the brush is good for not ripping hair out, while the stiff bristles help for getting through the hair. The ball ends feel nice on my scalp. I brush mine after I get out of the shower, and it keeps it looking nice. A friend of mine doesn't brush his ever (I know because his wife complains about it), and it sort of clumps into locks rather than being free individual strands and looks kinda bad. The key to brushing that no one tells you, and it only matters once it gets pretty long, is to brush in sections. Like, brush the ends, then the middle to the end, and then from the scalp to the end. This helps prevent tangles and get them out when they happen.

The thread from earlier about shampoo has a lot of useful information in it. I use my partner's shampoo and conditioner, and they have very different hair than I do (extremely curly), but it works well for both of us. I do buy into the buzz about sulfate-free shampoo, as it helped with the dandruff I used to have, but just not shampooing as much did wonders for my hair quality. I use a kind of expensive shampoo (a salon-only brand we buy online), but I only use it every few weeks, so the price isn't so bad over time.

As far as styling and styling products goes, I'm still figuring that out myself. My work prohibits hair product (specific manufacturing environment), and I haven't really been going anywhere since the pandemic shit began, so I'm just now thinking about it.

As far as hair ties go: ones like this are pretty good for my hair. They don't tangle, since the elastic is covered by cloth. Scrunchies just slip out, but they're good for curly hair. However, don't put your hair up too tight or too often, as it'll start pulling your hair out at the root, starting at your hairline in the front, and you'll freak out that you're balding even worse than before.