Some one has added information to my tree that I believe is incorrect how do I delete the people I do not agree with
If you have folk in your tree that you believe do not belong, they can be removed. Go to the person's page. Scroll down to family. Under the parents, click on the pencil beside the incorrect child. Remove the child. If the spouse is incorrect, click on the pencil beside the marriage information and remove the spouse. Hope this helps.
To elaborate a bit on the other answer's advice: because this is a collaborative tree, profiles generally shouldn't (and can't) be deleted. If they don't belong where they've been put, it is the relationships that should be changed.
As an analogy, imagine a family reunion activity where everyone contributes index cards representing the people in their branch of the family, arranged on a large corkboard with pushpins and string to represent the relationships. Now imagine if there were multiple reunions going on, and the cards for this game got scrambled, so that your corkboard suddenly had people from someone else's family on it. You wouldn't throw those index cards away, nor write all over them, right? You'd move them instead (into a box for transfer to the other family's room). The Family Tree on FamilySearch is kind of like a very-overgrown version of this scenario, and people mistakenly attach cards to the wrong corkboard All The Time. Correcting their errors almost always consists of moving the cards, not of writing on them or throwing them away.