There is no credit for being a FTB. The Government had a tax credit for buyers 2 or so years ago, but that is no longer.
Here a a few credit that any buyer can get
1) Realtor credit - your agent agrees to credit you some of his/her compensation for your closing costs
2) Lender credit - the bank/broker doing your mortgage can give you a credit for your closing costs. This credit will be attached to the interest rate you select. Higher the rate, greater the credit.
3) Seller credit - You can have your Realtor draw up the contract where you receive a credit from the seller for closing costs. This is done by increasing the purchase price by say 10k, and then having the seller credit that amount back. Your essentially financing the closing costs this way
4) Tax credit - this not so much a credit as a deduction. You get to deduct the interest on the mortgage. Check with your CPA as to how much this would be.
If your talking about your minimum credit score, then you'll need a mid score of 580.