Posts not showing on new wordpress installation

I hope this is the right forum to post this in. I just installed the newest version of WordPress and it appeared to install correctly, but the posts won’t show up. Currently the only post there is the default “Hello World” post…but when I go to the URL displayed for this post it comes up with the “coming soon” message our host put up.

We installed it on a subdomain of our site (blog.example.com). I took all files/folders from the wordpress file was the downloaded and installed them directly into the root of the subdomain. Was this the correct way to do it?

I’d also like to have blog.example.com/index.html show an index of the blog if this is possible, like an opening page with a short explanation and a list of blog categories.

I’m at a loss for what else to do to fix this, please help! Thanks.