Wix, Squarespace and similar.
THE HARD TRUTH
Builder sites generally cannot be exported in a usable form.
You are rebuilding, not migrating.
WHAT YOU CAN SALVAGE
Your text content, by copying it Your images, by downloading them Your page structure, as a plan
WHAT YOU CANNOT
The design The functionality Anything built with the platform's own features
HOW TO APPROACH IT
Treat it as a rebuild with existing content.
Plan the pages, gather the content, build on WordPress or another platform.
WHAT TO PRESERVE
Your URLs, where possible.
Keeping the same page addresses preserves search value and existing links.
Where you cannot, redirect the old addresses to the new equivalents.
FOR YOUR DOMAIN
If it was registered through the builder, you may need to transfer or unlock it.
Check that early. It is frequently the obstacle.
FOR EMAIL
If email was provided by the builder, it ends when the service does.
Plan the mail migration separately.