When you try and make a website and you don’t know where to start it’s going to be complicated.
First you want to know what type of website it is. Pure HTML CSS? Framework? PHP?
If your answer is pure html css, neocities can be a good webhost for you. or github pages. Many websites like this are made using neocities.
github pages also works if you want to use a framework like Angular. I myself used github pages for my website. I use My own scripts to host my angular on Github pages.
To host your obsidian vault on the web, go here.
But then there is the question of a database and backend, where to host that? Try 000webhosting if you want free php webhosting. I used php webhosting for the following: https://oldmartijntje.nl/Chat