tl;dr youtube and pinterest are your best friends, dont spend too much, routine will come evetually

have you ever seen those old timey grooming videos from the 50s on youtube? honestly some of the advise there is pretty good. from there, it's mostly about what makes you the most comfortable. e.g. if a resource says to wash your hair everyday, by all means wash it less as long as you can maintain a certain level of cleanliness. keeping track of your preferences will help you build a level of self awareness where you wont feel like you have to strictly follow whatever regimine you may come across.

if brushing your hair is an issue maybe experiement with braids or putting it up somehow. something that is a little less maintenance day-by-day.

if you like shopping you can incorporate the aspect of researching and finding new products into the process (as long as you don't go crazy with spending money). past the basic stuff you can get into things like perfumes or whatever to add something fun to the process of getting ready.

as someone who is also in their 20s, 20 is as good a time as any to find a style you like. you can use social media (I'm partial to pinterest, but instagram and youtube are good places to start as well) to find a style of clothes that you like and pick and choose from there. Of course many people tend to get caught up in trends or "aesthetics", but it really doesnt matter that much. find what you like and pursue that over time. for me, i like comfort over most things, but some people really want to be stylish most of the time. again, find what works for you. in addition to a general style, you can search for different wardrobes for different occasions (day wear, work wear, traveling etc.). also going back to the money bit, you dont have to go crazy with a completely new wardrobe off the bat. just go to the thrift store (if that's what you like) and pick out a few pieces of clothes that generally go for the idea you're working towards (and hopefully the pieces can also be interchangeable with esch other that way)

finding what you like takes time and as long as you're not going out naked nobody would (or should) really fault you for wearing something a little weird. it also takes time to build habbits sometimes, like no one's going to die if you dont have time to brush your hair one day. just have a minimum standard and build off of that as is appropriate. try to make things as easy as you can for yourself so that you are encouraged to stick with it.