You can access Google Chat by visiting chat.google.com or by going to google.com and clicking on the Chat icon in the menu at the top right.
If you have a Chromebook, you can also press the magnifying glass key on the keyboard.
Feel free to download Google Chat as an app on your mobile. But don't forget to log in with your school account.
Find the person you want to chat with and get started! Click on "New chat" in the top left corner and search for a person or a room.
Click on the person's name in the left margin. On the right, type your message in the box with the text "History on." Press the "Enter" key or click the arrow icon to send the message. You can also attach files or have a video conference with the person you're chatting with.
You can upload files, but the easiest way is to attach a Google Drive file. You'll be asked what level of access the person you're chatting with should have to the file.
You can also create a chat room, or a "Room" as it's called in Google Chat. In a room, multiple people can communicate with each other simultaneously. Everyone in the room can see what is posted there. Anyone, including students, can create chat rooms.
Here, you and your class/group/team can have a room where you can chat and work together. Just remember to set clear rules!
Click in the box "Find people, rooms, bots," then click on "Create room."