there's
a thread here on melonland for people looking for penpals if there is a community college near you they'll have writing classes, if you want something structured; there's also virtual learning resources like khan academy, coursera, and masterclass, which have varying amounts of structure/guidance/feedback. (also, most classes will probably involve
some amount of writing, even if it isn't writing-specific.) you could check at your local library or other community center to see if there are any writing groups or classes offered through there - and, if not, you could ask around about how you could start one!
lots of hobbyist writing websites have various how-to guides;
scribophile and
nanowrimo, for example.
there's also lots of books written about how to write, how to improve at writing, etc, if how-to books are helpful for you.
if there are specific writers you like or want to emulate, you can look into seeing if they've done writing about advice or their process or writing in general (like stephen king's
on writing, for example), or try to take some time with their work to try to identify what about it you like.
reading a lot in a wide variety of styles and genres helps a lot with identifying styles and techniques that resonate and don't resonate with you. doing a lot of practice reading is very helpful in developing an eye for what "feels" right and other nebulous things like voice, tone, rhythm, mood, pacing, etc. read work you think is good and think about what about it makes you think it's good; read work you think is bad and think about what makes you think it's bad; etc. even if you know there's only one specific type of writing you're interested in doing, i think it is still helpful to explore broadly so you don't feel boxed in or like there is One Single Way to be good at writing!
and, of course, practice! you could join a blogging community if a social component is important to you. there's stuff like the
indieweb blogging carnivals for example.