'Il faut cultiver son jardin' ( [first]One must cultivate one's own garden) as Voltaire said, in other words, start with yourself, and when you've put that to rights, then start on the World.
Tentatively at first by I suggest when you go out, start by picking up litter; take a bag and either a glove, or better, a litter picking-up tool.
When you get back home deposit it in your dustbin, make yourself a cup of tea and relax with the thought that the World is now just a little bit better than when you went out.
Leave the big stuff to the idiots, there's nothing you can do about it, they have full control.