When i bought my dahlia flowers, there were some dead leaves and flowers. is it right that i pulled them off?

Question:for example, a leaf was ok except for the end of it. so i pulled off just the end, is that what im supposed to do? and a flower's pedals looked like they were dying so i pulled off the flower and left the tall stem. will another flower grow on that stem?

Answers:
Yes.

Taking the leaves off doesn't make things better or worse but it looks nicer.

Taking off the old flowers is 'dead heading' the more you do that the more blooms you will get.