I'm not sure where you're from, but in North America (and many other areas) societal norms are being challenged and I think our view of "adulting" is put on us by older generations. We're told from a young age: go to school, get good grades, go to post secondary school, get a good career, marry the love of your life, have kids, and usually in that order. That's not really reality these days. You don't necessarily HAVE to do any of these things if you don't want to. Unfortunately you will need to work in order to be comfortable, but you don't even need post secondary to get a decent job. Trades make great money and can be really rewarding. I sat behind a desk for years and had the soul sucked right out of me. Meanwhile, I worked in a farm supply warehouse lifting bags of feed, spreading seed, and operating a forklift and I LOVED that job. Working isn't always hell. Working a job you hate is. There's lots of great, fulfilling jobs out there that can fill your cup. Being happy is way more important than being successful financially.
Look, I'm almost 37. I've been married, divorced, and now in a long term partnership with a child. I still don't know what the fuck I'm doing lol.
I've also realized now that I'm older, that my parents, and grandparents and all other adults don't overly know what the fuck they're doing either. It's kind of a "fake it til you make it" mentality. Life is strange. Don't focus on the expectations of being an adult, and focus on what you can do to fill your cup mentally as you move into that phase of your life.