The Google Daydream comes with a small handheld remote that is completely functional inside AltspaceVR. You will launch into a tutorial when you open AltspaceVR for the first time in VR mode. Once inside the virtual space, you will notice you can see your own remote in front of you. If you lift the controller to your face it will show you a button map of all the remote's functionality as seen in the picture below. You can check this at any time. Follow the instructions in the tutorial and you should get the hang of it quickly!
You can click on the outer edges of the thumb pad to move forward, backward, and to turn left and right. You can click the center of the thumb pad to interact with menu buttons, avatars, objects in your environment, and even to teleport. The menu button will open up your AltspaceVR menu window. Swiping your thumb across the thumb pad will allow you to scroll up and down in any windows that have a scrollbar present.