If your school's WiFi is blocked, there are a few ways you can try to connect. First, see if there is a way to get around the block. Some blocks can be bypassed by using a VPN or proxy server. If you're not sure how to do this, you can search online for instructions specific to your device and operating system.
Another option is to use a mobile hotspot. This will allow you to connect your device to the internet using your phone's data plan. Be aware that this can use up a lot of data, so it's best to only use this method if you have an unlimited data plan or if you're only going to be online for a short time.
Finally, if all else fails, you can always ask the IT department for help. They may be able to give you access to the WiFi or help you troubleshoot the issue.