A cat sheds it's old nails on occasion just as a snake sheds it's skin. It allows new growth to come in better. If you do not see any sign of blood and the kitty is walking normally then you have nothing to worry about. Clip the nail as you have the rest. It may help it come off easier.
No question is a dumb question. I would rather a new pet owner ask a hundred "dumb questions" then not and do something that may jeopardize the health of the pet.
Welcome to Pets. ca. Pics of the new family member would be wonderful!!
Assumptions do nothing but make an ass out of u and me.
We can stick our heads in the sand for only so long before it starts choking us. Face it folks. The pet population is bad ALL OVER THE WORLD!