website is with zoho

email is hosted by google.

want to move email to zoho but i want to change email address to a new shorter domain address nortex-ins.com. 

do i make the new shorter domain address nortex-ins.com my primary domain on zoho and set up email like is new service? and if so how do i handle my old email at gmail? 

i would like of a email is sent to the nortexinsulationservicellc.com to merge into the new nortex-ins.com. is that possible? 

i'm looking for the smoothest transition.. and please when responding, explain things like im a 2yr old. setting up the zohosite and gmail were both first for me. ( Self taught mostly thru zoho, just want to say zoho makes me look like a genus to my boss) 

thanks, rickanna for leroy