I think one of the most common reasons why well-meaning people might not try to take action against an issue as big as racism is a simple feeling of being defeated before we start. There's a tendency to think, "The forces of prejudice are so massive and have such inertia that nothing I can do will make any sort of difference."
But I think that in this, as in so many other things, small steps should not be discounted or dismissed.
You might want to ask yourself, "To how many people do I need to make a difference before I can count it as worth while?"
Is "one" really too small a number?
Maybe not for a start.
I am talking to myself here as much as to anyone else. Once upon a time, perhaps more than 20 years ago, I made the day for one young man at a science fiction convention simply by making it clear that there were people of color among the pre-made player characters I had prepared for a roleplaying game I was running in Open Gaming. I don't know exactly what was going through his head when he grinned widely and exclaimed "He's black! This dude is black!" but it was something pleasant.
But now I think, wouldn't it be even better if a young person of color wasn't astonished to find him- or herself among the characters or a game - or a book - or a comic, because it was the norm?
I need to do more. I need to do my part so that the day I've just described will arrive.