If you are not in a school, then you can still observe Gaia Alerts! Using a small telescope, many Gaia Alerts will be bright enough to observe. As telescopes vary in aperture (and hence in their sensitivity), it is not possible to give precise guidelines on exposure times. However, as a rule of thumb, a magnitude ~14 Alert will be observable by eye in a 6-inch telescope from a dark site, while a magnitude ~15 or 16 Alert will be detected in an image taken with a small telescope and a CCD camera.
We have developed a web-portal, the Cambridge Photometry Calibration Server, where you can submit observations taken with any telescope, to help us monitor Gaia Alerts. You will have to register to be able to submit your data - please follow instructions given in the CPCS Manual.