Moving WordPress

the addon domain has an existing site so i need to know if i just delete everything from that folder and move all wp files into the directory.

Can you be more specific with details? One option you have is to just leave all existing folders and files exactly as they are while adding a new folder beside the existing one and making a new WordPress installation there by simply going to cPanel and re-pointing that domain to the new folder. By doing that, you could even switch back and forth between the two locations at-will like while working on the new site during off-hours and putting the older one back up at any time and just as it has always has been. There are other options also, of course, but the actual end goal must be known in order to sort through them.

I have already built the wordpress site, so i can remove all the existing site files and replace with the wordpress site files that have been built in a subfolder. all i’ll need to do is physically move the files. From there i will go through the entire database and site files. i will then update both the URL, and the file path throughout my script.

I have already built the wordpress site

That adds up to its database, its /wp-content/ folder with all content, your wp-config.php file and your root .htaccess file. You can replace all the remaining every-site-has-the-same wp-folders and wp-files if you wish, but that is not required and I would use fresh ones from a new download if I did.

From there i will go through the entire database and site files.

Since the database and /wp-content/ are already a paired match, there really should be no need for that unless they need work even right now.

i will then update both the URL, and the file path throughout my script.

Again, there should be no need there if the database already knows to accept the URL and you use cPanel to simply re-point the domain to its new location. And if you presently have something like mysite.com/subfolder in the boxes at Dashboard > Settings > General, that can be corrected all at one shot with just two temporary lines near the top of wp-config.php the first time you access the site in its new location.