Canadian Citizen applying for Residency

[amadhani]

I'm a canadian citizen, visiting my daughter in the US, who's a US citizen. I would like to file for my residency while still in the US but am confused about the i-485 which requires me to put in my 1-94 # and the date I came to the US. Evidently my entry was through Niagra Falls port , which being the way it is, never stamped my canadian passport or assigned me a i-94. What should I write in that section that requires i-94, current INS status and the expiration date. Is there a resource online I could use to fill all the documents out or do you guys suggest I use an attorney. I'm short on cash...Thanks

Amin