I've messaged you with some info, but here's some starting points. First things first, make sure you've got an accessible theme. You can still work with those that aren't, but I've found it to be a lot easier to work with a theme that fits what I want rather than editing one. WordPress has a pretty comprehensive list of accessible themes posted somewhere (a quick google search should find it), complete with really good descriptions of what it looks like and what features it has such as layouts of menus and sidebars. Just make sure you're looking at the themes for wordpress.com and not wordpress.org. Next, most of the usual stuff can be found at the bottom of your site if you're logged in. The first link in that menu is called "Customize", and there should be links below that to add posts and pages. Clicking on "Add" for any of those should bring up a blank one, and all the fields should be accessible if you have it set to the visual editor, which can be changed by two radio buttons near the top which change between visual and HTML views. I've not found the HTML editor to be accessible, but you can still write HTML into the visual editor field for the main body if you want which I've found to be faster if you're proficient enough with it instead of using the visual editor tools. And speaking of the visual editor tools, there's a button near the bottom of the available ones, just above the main body edit field, which should open up a list of keyboard shortcuts for some of the basic functions like adding headings and links. Adding pages is a little trickier, but you just need to get the hang of using the menu system to make sure the links to the pages are displayed in a menu if that's what you're going for. If you're adding it to a widget or linking to it from another page, using HTML code is you're best option in my experience. Finally, some of the bigger changes such as editing menus and widgets can be done with better accessibility from your site's dashboard, which can be found at your site's URL plus "/dashboard."