Hi,
This could happen if you signed in with a work or school account during setup, if your device is enrolled in a management system, or if it was pre-configured with policies from a previous owner. Is it a brand-new laptop?
To regain full access to your settings, you can check your account settings in Settings > Accounts > Access work or school and remove any accounts you don’t recognize or no longer use. You can also check if your device is managed by going to Settings > Accounts and looking for any message that says your device is managed by an organization. If you're comfortable doing so, a clean reinstall of Windows can remove any lingering management policies and restore full control.