The answer is ::
"We invite the boys to a youth party."
You need a correction : our kids (wrong✖)
correct one is. : the boys(right)
Explaination word by word:
Nosotros : We
invitamos : invite
los : the
chicos : boys
a : to
una : a
fiesta : party
de : of
jóvenes : youth
Join the words : We invite the boys to a party of youth
or we can write it as : We invite the boys to a youth party.
hope you understand