Hi @fortsferryfarm. Thanks for being part of GoDaddy Community! Since you're planning on using the same provider for both website and email, you'll want to update the nameservers for your domain to point to that provider. Usually, providers will set up your domain for use with email when you use their DNS by default, but you may want to double-check with Squarespace just in case.
As for moving your emails over, there isn't always an easy way to do this. You'll, of course, want to set the emails up with Squarespace before making changes to your domain's DNS. That will allow you to continue receiving emails while the DNS change propagates. However, whether you'll be able to move over your existing emails and how you would do that would depend on what kind of email plan you have now and what you'll have at Squarespace. One way that might work if you use an email client like Outlook would be to set up a new inbox for the new address while keeping the old one active in the client. Then you can try copying the emails from one box to another within the client.
JesseW - GoDaddy | Community Manager | 24/7 support available at x.co/247support | Remember to choose a solution and give kudos.