This page provides information about climate strikes and direct action you can get involved with.
This group is a branch of Exction Rebellion specifically for under 30s. They hold fornightly meetings and they have more information about this here. You can also find out more about Extinction Rebellion here.
This is an international movement, begun by Greta Thunberg to protest against the lack of action on the climate crisis. They have created this Digital Toolkit about striking online.