On a phone or tablet you can download the Classroom app:
Otherwise, the quickest way is to go to the front page of the school website and click the Google Classroom button:
If you have signed in previously, you can just click on the correct account to go straight in. If your school account isn’t shown, just click Use another account.
It will then take you to a page where you can sign in with your @alnsconnected.com email address and your normal school password.
Once you are in, simply click the class you want to access to open it.