Hey Baby82dove,
Thanks for visiting Apple Support Communities. I see that you’re having issues installing the iOS update and I’d like to help.
If the installation fails with that error message, I recommend that you delete the iOS download and download it again. Make sure that you have a stable network during the download. Also, try the following steps from this article: Get help with over-the-air iOS updates
If you continue to experience the same issue, you can update the device using a computer. Here’s how: If you need more space for an update
Have a great day!