How do I remove this?

The short answer is: you don’t. Apple Intelligence is part of macOS and the components are downloaded and stored locally regardless of whether or not the feature is enabled.

The long answer is: you can, but it’s not for the inexperienced. Steps involved booting into RecoveryOS, disabling system protections, then using Terminal to delete the frameworks and generative models.

"System Data" comprises your data, but they are files that Spotlight cannot assign to a specific category like Documents or Applications. Examples include Outlook attachments, Cloud storage caches, and Time Machine snapshots. 

See this User Tip:

How to free up ‘System Data’ and other st… - Apple Community

Yes, it is.

weeklycod wrote:

can I delete my wallpaper,s video

It’s your Mac. You can do whatever you want with it.

But if the data is valuable, have backups.

As you are undoubtedly also discovering, being low on free space does mean the on-going managing that (lack of) storage can be necessary, too.

weeklycod wrote:

will it harm it, that's why

Have at.

MacOS can be restored using Recovery or using a bootable installer you may have created, and you will gave made backups of any data you value.

You’re intent on learning by breaking things — one of my own favorite learning techniques — so — once you have good backups of any data that matters to you — go learn, delete, erase, experiment.

weeklycod wrote:

https://discussions.apple.com/content/attachment/f3df43ae-8126-48ba-933b-055e5e7b51ec

how do I remove this and

https://discussions.apple.com/content/attachment/03592f88-dc3e-46f7-914a-a2fedac17041

this, I don't use apple intelligence

It sounds like you are getting low on disk space. If Disk Utility (the only reliable tool for determining free disk space) shows less than 15% free you are in some danger of impeding the normal functioning of your Mac.

System Data of 31 GB is actually very low for that category, which as neuroanatomist points out can contain a collection of different things, many of which consist of your own data files. My Macs have between 60 GB and 90 GB of System Data. For me much of that is due to multiple Photos Libraries I have in my Pictures folder, as the MacOS Storage tool assigns only the primary Photos Library to the "Photos" category and all the others seem to be assigned to either "System Data" or to "Documents."

To save on your disk space, consider moving all your Photos Libraries and Music to an external drive. You can delete Time Machine snapshots from within Disk Utility, which can temporarily save tens of GB but the system automatically recreates them over time.

You can turn off AI in System Settings that will give 2-3GB more storage but that is not much.