Yes, install on the new PC and transfer the company data by doing a Sage backup and restore.  Its the cleanest way to migrate the data and if you actually use the Archive feature it will migrate those when you do a restore (their is a check box to include archives). Its also a good idea to copy the company folder over but don't put it in the same directory, just create a OLD_Company data folder on the drive as it could have some old backups or files that could be needed.  

Thank you!.  Once I install on the new computer, I know i can copy over the Customer Number and Serial Number, but how do deregister the old one so Sage doesn't want to charge me for a new license, or do I just stop using the old one on wifi?

You don't have to do anything for the old one if you have the same customer number, they will not double charge you.