that sounds fun! making things for yourself IS a really pleasant and freeing experience 
don’t let the insatiable gaze of hypothetical strangers mess with your process!!
i think forums make a lot of sense to me as a way to organize your thoughts :) i like the organization format of threads and categories and such… my discord server for my four friends and i has a bunch of channels. it feels very tidy 
on the private-website side, lots of people make personal wikis! tiddlywiki for example has a whole subculture, and i know it’s not the only personal-wiki setup out there… and we have our startpage thread here! i and plenty of other folks have private homepages we made ourselves! it’s fun, its like having a secret hideout 
my regular site is mostly just for me too! it isn’t private, so it’s not exactly the same thing, but the thing that makes it easy and fun for me to work on is completely disregarding other people and what they might think about or want from my site!