What is the best way to do the following?

I am with Titan Toastmasters #2368.   I am the VP of Public Relations 
I have set up Go Daddy's Domain which I bought.   I know I need take the Domain through Free ToastHost Titan Toastmasters webpage.   As I understand it, you type the domain in the custom domain page.  Do I delete Titans? Right now as you can see from the screenshot we are using the toastmastersclubs.org domain.  When I put in the new domain, will the emails change?   Can we still use the toasmastersclubs.org or do I need to update the email address?  
Do I need to get a certificate for the new domain?  If yes, what kind of certificate should I get?  If I need any help with any of this can I get in touch with a tech?   
Can you Please let me know the next steps I need to take?   Can someone walk be through this?
Krispin Andersen

Please refer to the documentation here
support.toastmastersclubs.org/doc/item/d...tical-considerations
support.toastmastersclubs.org/doc/item/dns-settings-overview

Your domain settings look good - there seem to be some superfluous A records
You can leave the alias for a while - see the documentation
Once you have entered the custom website domain in the "box", it will take a few hours to come into effect.  The SSL certificate will be provided by FTH
Both sets of the email addresses can be used 
The addresses shown in the club email addresses will depend on whether you log in using the custom domain or the website number (or alias)