1040 form for 2017. I am purchasing a house and need this information and I do not remember if I filed Last year, how do i find this?

You do not even know if you filed a 2017 tax return?  Then first check to see if the IRS has a transcript of a return you may have filed.

You can get a free transcript from the IRS:   

https://www.irs.gov/individuals/get-transcript