Before you start adding content to your website, familiarize yourself with the basic digital accessibility concepts you’ll need as a site editor. Starting with accessibility in mind will save you significant time and effort later and help you keep your site accessible.
The CoE Accessibility Site’s Five Core Skills give you the tools to avoid the most common accessibility pitfalls.
There are also many other tutorials online. Here are some examples to get you started, including one from WordPress and one from the University of Michigan:
Once you have made some adjustments, you can test the accessibility of your website with online tools such as http://wave.webaim.org.