Microsoft Teams allows for quick and easy communication and collaboration of resources with a team or on a one to one basis.
Teams can be access from any device with an internet connection by simply logging into your office 365 portal using your school email address and password via the below link:
once logged in, you will be shown the landing page of office apps and you can select the 'teams' app as shown below:
Attached to this guide is a Microsoft Quick use guide for using teams which is great and will provide the basic information to get you started.
For more videos and training, please use the below link for all the information you need on how to use teams.