How do I let users design their own blog with trix

I know how to use trix in a field but how do I let users design their entire page?

Trix is designed to be low- or no-design. The kinds of elements you can create with it (H1, P, FIGURE, UL, OL) are not, on their own, enough to create more than a word-processing-style page "layout". You could let the user have access to a stylesheet, and they could write some clever CSS, like, say, targeting the third paragraph and making it a pull-quote, with borders and margins and float, but that's not really the same thing as giving someone a full set of WYSIWYG controls where they can make the page look like anything they want.

Walter

I know how to use trix in a field but how do I let users design their entire page?

Trix is just a relatively small content editor - you might want to have a look at a CMS solution like this one https://github.com/comfy/comfortable-mexican-sofa, where you can prepare layouts and pages for the users to fill (with such an editor). It’s not as advanced as a modern CMS though and might not suit your users needs enough.

Niklas