Hi, welcome.
No, it is not possible to replace Ubuntu with Zorin and keep everything from data (/) .
You can backup data and specific folder only.
If you have Ubuntu on 2 separate partition, root on one and home on second, than you can use those "home" partition on Zorin
Then, off to the Rescuezilla and read and study.
It is a stand alone software and you need to create a bootable USB to use it. Whole procedure is in GUI and beginner friendly.
In fact, I made a Rescuezilla USBs and gave them as a Christmas gift for my husband in addition to his daughter. The super penguin is absolutely cute!
Alright, thanks.
I do not want to risk my data. I'll just follow backup and restore.
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What do you mean by data? Personal files and/or applications?
Applications will have to be reinstalled. There is a how to in the tutorials and guides section that will make that easier (perform prior to reinstallation).
It depends on how you installed Ubuntu. If your home directory is in the same partition as Ubuntu, i advise saving that to to a usb. If it's in its own partition, you will mount it in gparted during the installation at /home, without formatting. Then you can choose something else in the Zorin installer from the live cd. In the partition window at the top, scroll to the Ubuntu partition, format to ext4 and choose mount point /. In the unused space, create a large partition, formatted as ext4 and mount as /home. Choose the efi partition to install the bootloader from the dropdown list. After the installer finishes, copy home contents from usb to your /home/[username]/ directory. This will save your data and some of your configurations.
You may want to read up on partitioning prior to partaking this endeavor to have a better understanding.
Note: home stores your downloads, documents, videos and pictures. This will prevent personal data loss.