@ultraloveheaven so, your main page is the "index.html" file in the "Home" folder on the neocities dashboard, yea?
1. add a new folder to "Home"
2. make your 'more accessible version' the "index.html" there
3. add links to each other on both pages to switch between them
(main page has a link to accessible page; accessible page links to main)
i did it this way because my alternative is html-only (which was easier to code) and i have a personal challenge to avoid javascript.
html-only means the site will be read however the user's browser settings say, which is better for people who have to use accessibility-focused browsers.
if you just want your custom site but with a more flexible (mobile-ready) layout, focus on the CSS and use a button, link, or drop-down menu to change the theme (like how people have themes for different backgrounds, day/night etc). that's making a javascript event that switches css elements or entire stylesheets, though.
looking up "theme switching neocities" can get you started there. 'squidknees.net' is a great example of an accessible personal website.