Well, without knowing what add-ons you use.. nobody can tell you for sure..
But if you can use the 8.0.x line, you should (if all your add-ons and XF is up to day) be pretty much assured you will be OK.
As for "how do I do that"? again, more information is needed before you can tell for sure. Did you roll out your own LAMP stack on a VPS/dedicated server? Are you using shared hosting? If so, what panel are they using?
With cPanel, the upgrade to php 8.0 is a fairly easy process, and should be have the instructions on your hosting provider site, or at least the ability to submit a ticket to them to inquire (that's part of what you pay for on shared hosting).