Changed my domain name but old one still appears on google and it does not work

Hello!

New to any form of website design, so please go easy!
I recently realized I needed to change my domain name. I had a built-in domain from Squarespace that used to be  https://decagon-clownfish-rfas.squarespace.com/. I changed it to something related to my business name (littlerockcrashpad.squarespace.com) and though the change is confirmed on Squarespace, when I search google with my business name, the original domain name still shows up (decagon-clownfish-.....)- and what's worse is that when I click on it, it says "no such website." What should I do? How do I ensure my website still exists when I google search Your Own Crashpad or Little Rock crashpad? 

Thank you for any and all help!!

I'm not aware of any way to redirect an old built-in domain to a new one. The built-in domain name can be used as the primary means of accessing your website, but you're generally much better off using a custom domain.

3 hours ago, Ziggy said:

I'm not aware of any way to redirect an old built-in domain to a new one. The built-in domain name can be used as the primary means of accessing your website, but you're generally much better off using a custom domain.

Thank you for your reply! 

I currently have a custom domain set as my primary domain (it is yourowncrashpad.com). I’m trying to redirect my old built in domain to my new primary custom domain  (yourowncrashpad.com)

My old built in domain still appeared in google searches even when I had it set not to via Squarespace. Not sure if that amplifying information helps. I believe that occurred because I published my website before changing the setting to hide the built in domain from google. 
 

Again, thanks for any help you can provide!

18 minutes ago, YourOwnCrashpad said:

I believe that occurred because I published my website before changing the setting to hide the built in domain from google. 

That'll be it, it's surprising that your old built-in domain got indexed, but it should correct given some time, I still don't think there's anything you can do to redirect it.