What forms do I need to withdraw from my retirement for a 1st home.

if you dip into your account to buy a first home then, your financial institution will report your withdrawal to the IRS and send you a 1099-R statement just after the end of the year; when you take the money from your IRA, you need to tell your financial institution that you are using the money for a 1st home and plan to claim the exemption. When you get your 1099-R statement after the end of the year, it should contain code "2" in box 7, which tells the IRS the distribution is exempt from the penalty , I mean 10% early withdrawal penalty not income taxes. If the box contains another number, or is blank, you need to contact the institution and ask for a corrected statement. The 1099-R form is informational only. You don't need to attach it to your tax return UNLESS federal income tax was withheld and an amount appears in box 4.
If your 1099-R does not contain a "2" in box 7, and you do not have a corrected statement, you will need to fill out Part I of Form 5329 and submit it with your tax return. On this form you will enter exception number "09" on line 2 to indicate the withdrawal was for a first home.