I ordered another domain name. Now I have two with inmotion. I want to have an email address with the second domain name. I am a novice and not a professional IT guy.

I am getting off my comcast email service that I have had for over 25+ years.   I don't want to use google, so decided to stay with InMotion.   I ordered a new domain name (now I have two) that I want to use as my primary email domain address.  How can I use Inmotion as my email client?   I apologize. I am not savvy at all about IT.