What if a site is downgraded from premium plan to free one?

Is the site still available and accessible if is downgraded from premium plan to free one?
What features will be removed or blocked after downgrading?

Does anyone have experience about this? Please help!

Your question is not a code related issue which this forum is for. You are better suited going through Wix Support for more help. https://support.wix.com/en/about-wix/contacting-wix-support