How to hide header from all pages except Home Page? At the same time, I want to keep footer on ALL pages. Is this possible?

You can’t, you either have header and footers shown or pages without header and footers.
https://support.wix.com/en/article/hiding-the-header-and-footer-on-a-specific-page

You would have to have no header and footer and simply make up your own footer and set it to appear on all pages or set it in the site code tab to appear on all pages. The same with your header just for the home page.

This is not a code related issue and you would be better suited going through Wix Support for more help with this issue.
https://support.wix.com/en/article/contacting-wix-customer-care-for-support

Search the forum and you will find same posts on this like here.
https://www.wix.com/corvid/forum/community-discussion/how-to-hide-footer-for-one-page-only