Hi, please pardon the silly question but I am new at using the stand mixer. Could someone tell me which attachment to use for these cookies?...

The paddle attachment is what you're going to use for just about everything. The balloon whisk is for whipping things like egg whites and cream, and the dough hook is for heavy doughs (like yeasted breads), where it takes the place of hand kneading.

It's not a silly question at all, it does not say in the recipe what to use but in opinion it would be the paddle attachment.