There are many ways and you can find which ways work best for you.
Have a look at this thread:
In your case, you would need to skip the first section on repositories, and instead search out the Next Release Repos that you need and add them. Then, follow the second section to install you current software all at once.
Some software may need to follow different steps - such as anything you built from source.
And you will want to ensure you back up your saved configurations from your Home Directory and move that over to the new install.
Please keep in mind that a next release will be based on a later version which may not have support for older packages.
For example, Zorin OS 15 was based on Ubuntu 18.04 - Bionic Beaver.
Zorin OS 16 was based on Ubuntu 18.04 - Focal Fossa.
If you have installed packages from Bionic that the developer of those packages (Independent Non-Zorin Developers) have abandoned, no longer maintain of have not yet upgraded to Focal Repositories, you may not be able to roll them over to the next Release of Zorin OS.
The terminal will notify you if this happens with a warning:
"Warning: PPA does not contain a Focal Release File"
If you see that warning, you know that the package is not upgraded to the Focal Repository.
Sometimes, you can still install it by installing the .deb package as long as all dependencies are met.