Waves/curls can be affected by hormones, so yes it can get wavier as you get older, mine got wavier with each pregnancy.
Look up the curly girl method - there’s lots of info and it can seem quite a lot of work, but most people treat it as a bit of a pick and mix method, ie only do the bits that work for them.
brushing mine does indeed make me look like I’ve been dragged through a hedge backwards 😂
I only use shampoo, my hair is real fine and any moisturising products create build up instantly, so no conditioner, cream or oil.
i work gel in when it’s soaking wet, scrunch it a lot, then diffuse it till it’s dry and scrunch out the crunchy cast from the gel… it does take about an hour, an hour and a half to do - but if I clip it up and wear a buff or bonnet to sleep I only need to wash it every 4/5 days. So it’s very labour intensive on wash day, but I literally just shake it out in the morning till the next wash day.
which was very long and probably too detailed given that’s specific to my hair - but it was to try and illustrate that yes when you look up curly girl it’ll look like loads of things and hours of work every day… but actually when you figure out what works for your hair it can be fairly straightforward