Go to https://socrative.com/ and click on Login to sign as a student. Students don't need to create an account so they can connect to teachers quickly.
Students will need to enter the room name provided by the teacher. Enter the room name and click Join to login.
As students join the teacher's room, they'll be able to participate in all of the activities that are launched until they log out. If there's no activity running, the message below will be shown:
Here's a guide for teachers on how to launch a quiz. Once launched, the quiz will automatically start for the students!