It’s okay if you are using Zorin, not Ubuntu.
If you want to replace Zorin with another OS, I have written a detailed tutorial on this topic:
If you want to remove Linux completely from dual boot, I have written about that as well:
Please note that it will be better if you have backed up your important data on an external USB/disk. Having a bootable Windows USB is recommended as a fall back option (in case you need to repair or reinstall Windows).
I hope this helps.