If these are chromebooks running Chrome OS, it is not a Microsoft product, but Google product. So it is not supported here.
However, even if this is Windows OS device, even if it is now your personal device, those restrictions were most likely applied through the school's device-management system. Unfortunately, this is not something a Microsoft/community forum or regular support agent can remove for you. We do not have access to your school's administrator account, management policies, or device enrollment records, and there is no legitimate Windows setting or command that can override those administrator restrictions.
Even if the school has given you ownership of the laptop, their IT department still needs to properly remove the device from their management system and release any policies that were applied to it.