PHP Update Causing Website Clone Issues

Hello,

I’m wanting to update a website’s PHP, so I created a clone using UpdraftClone to test this out. When I log into the clone site, WP still tells me the PHP is out of date (7.4–I know, super old), but when I go into the Updraft account, it says the clone’s PHP is 8.4. I notice that on the clone, a few pages of the website are not showing up like they should. I assume this is from the PHP update, but is there any way to fix these pages? I realize there may be a myriad of issues causing this. Or am I just going to have to find a way to re-create them? (Not a pro developer here, so sorry for any dumb questions.) Because the PHP obviously needs to be updated no matter what.

1. How do I know for sure what the PHP is on my clone site?
2. How do I update the PHP on my clone site? (It doesn’t appear on our webhost account.)
3. Is there a way to fix those webpages so they appear as they should, with updated PHP?

Thanks everyone.