To work with NVivo, you need to
- create an account for the myNVivo portal (What is the myNVivo portal?)
- download the installation file
- install Nvivo on your computer
- activate your license
You download the installation files in the myNVivo portal under the tab "Download NVivo" (you have to be logged in). You can also see your purchases in the portal (points 4 and 5).
After you have downloaded and installed the file you can activate it. Find all information about activation here: How to activate the New NVivo (2020)
You can also find download files for older versions of NVivo on the myNVivo Portal. But just in case you need to re-install NVivo 12, you can download the installation files here:
NVivo 12 for Windows:
https://download.qsrinternational.com/Software/NVivo12/NVivo12.x64.exe
NVivo 12 for Mac:
https://download.qsrinternational.com/Software/NVivo12forMac/NVivo%2012.dmg