So Kickstarter allows non-adults to start a fundraising campaign with parents agreement. But how about the taxes after they (teens) received their funds? What type of taxes does Kickstarter's funds count as. Do teens have to pay taxes for their fund (like maybe as income)?
Yes, money received from Kickstarter campaigns is usually considered taxable income. Who pays the taxes and how much (if any) they pay depends on how much the teenager makes, how old they are, and whether they are claimed as a dependant by someone else. For information about taxing children see IRS Pub. 929.
As pointed out in the comments, certain campaign contributions could be considered nontaxable "gifts" by the IRS. There are also taxable gifts but the taxes are paid and reported by the gift giver. You will want to talk to a tax professional about these. It is worth noting that interest on gifts is taxable unearned income unless the gifts were set up under a UGMA trust, which has its own rules.
You can deduct most expenses from income, as pointed out in the comments. This too is covered by Pub. 929.