Your website has three main areas –
- Posts – where you add news items
- Pages – where your main content is
- Portfolio – where your projects are
There’s also the Media Library, where all your images, animated gifs, pdf files, etc are stored. You can either add new media directly in the Media Library, or (as in most cases I suspect) add them straight on the page as you edit.
If in doubt, take a look at existing content and copy that method, or check how things are looking before publishing using the Preview button.
By and large everything is pretty intuitive, but don’t despair if things go awry, you can usually step backwards by using the Revisions tab further down the page.