WCAG Guideline 2.4.7 Make sure when you are Tab Navigating through your website that whatever the tab button is “focused on” an item that you have a way to convey that to the user. I recommend adding a high contrast box or ring around whatever your focus state is on. This way, a user knows exactly where they are when they are Tab Navigating.
WCAG Guideline 2.4.4 All of the links on your website have to have a secondary method of announcing they are links besides color. So this means that links need to be more than just blue. I suggest adding an underline when your mouse hovers over it or that link becomes the focus. This way the user has 2 different ways to tell that the text is actually a link. This has more to do with color blindness for users.
WCAG Guideline 1.3 Header levels (H1-H6) must be laid out like a document outline. For example, a H1 header should only be used as the main idea of the page usually the largest title text at the top describing the overall idea of the whole page. A H3 and H4 should be used as subsections within a H2. You can however use a H2 tag after you have used a H3-H6 tag if the new H2 tag is opening a new section or new content. W3C Header Solution
Data tables can be horizontal or vertical, with header cells describing either the column that comes below it or the rows that come after it. That means, table cells must be properly marked with a “scope” attribute so that the screen reader knows how to match the heading to the data.
Use whitespace and proximity to make relationships between content more apparent. Style headings to group content, reduce clutter, and make it easier to scan and understand. Remember, Spacing highlights relationship between content so use this power wisely.
WCAG Guidline 2.2.2 & Guidline 1.4.2 Provide visible controls to allow users to stop any animations or auto-playing sound. This applies to carousels, image sliders, background sound, and videos. I would suggest not to use any of these types of content if possible but if you have to then at least give the user control over them.