I was ordered to pay $50 a month for child support that I simply can not afford.if I pay $20 a month for now can I get introuble for not paying the whole $50.will they see that I'm trying to make an effort with what I have to work with?

Sure they'll see that you made an effort. However you still owe.

$50 a month is incredibly cheap. Pay the parent of your child.

If however, disability or dismemberment leaves you unable to scrape up that $12.50 a week, go back to family court and ask that the order be amended.