The money you hear about people getting for just filing a
tax return claiming kids requires them to
have some earned income (wages or self employment). Without earned income,
they are not eligible for the "refundable" Earned Income Credit or Additional
Child Tax Credit. Both credits are calculated on the amount of earned income you have. No
earned income means no "refund". A small amount of earned income
means a small refund. The child tax credit does not "kick in" unless
you have at least $2500 of earned income.
A child can be the “qualifying
child” dependent of any close relative in the household. If you live with someone
else, e.g. your parents, it may be better if they claim your child.