Any tech person to help please - Windows 10 E Mails not syncing - Desktop

There are numerous possibilities and you say you are not technically minded, therefore you risk creating more problems by blindly following some of the gurus on here. My first suggestion would be to contact support at your mail provider.

if you could detail your email provider and any software you use, such as outlook, and whether you use imap or pop or webmail etc, people can start to help

You probably already know but UNDER NO CIRCUMSTANCES should you divulge email address let alone passwords and settings on your account. (edited)

you used the term "syncing". With what? Has this always been the case or is it something new which has happened?

It sounds like you're saying the problem is that you're receiving e-mails fine and they're showing up on some of your devices but not your desktop computer?

If that's the case then the issue is with the e-mail program you're using on the desktop. You haven't said what that is (Windows Mail, Apple Mail, Microsoft Office Outlook, something else) or how it's behaving (error messages, not set up, says it's checking but doesn't find anything) so it's very hard to guess what might be wrong.