Moving from Subfolder to real domain name

Hey everyone,

I’m beginning to look into designing websites for other businesses using WordPress. My thoughts are to build it on my own website domain & server package as a subfolder of my current website (EX of a pizza shop https://www.mywebsite.com/pizzashop). Then if they were to like my site & service, I would move the site their either the domain name they own (Ex: https://www.pizzashop.com)or purchase a domain name for them. Most often it will be to their domain name they already own as most businesses I’ve looked into already have a site, just a really bad/basic one.

My questions is twofold, how would I do this? (Pointing?) and secondly, what do I do with the sites currently location? If the domain is with someone else, do I need to move it to a root folder or subdirectory on my server plan with GoDaddy, then enter their Nameservers, or vice versa.

Temp

Also, going forward should I have a different way of doing this? I tried WAMP & Local to live and it was a little too much for me, felt this was simpler on the install & live process, but it seems alot of the details are on the backend here.