2 Questions for a newbie in New York (TN)

any advice on the renewal of the TN?

by the way, in NY after 90 days of residency, you have to have a NY Driving license- I checked with the DMV twice.

To the original questions:

Getting an SSN is easy, present your passport and I-94 at the social security office. Work is even easier, when you fill in the I-9 you just give them the SSN, you can even use your Canadian DL as one of the proofs of ID. The only snag is waiting for the SSN.

As for importing the car, I had a car imported from the US when I lived in the UK and I thought it would be easy to take it back to the US.

After all the EPA inspection, customs, title registration, insurance BS I came to one very simple conclusion: sell your car - get a new one in the US. It's just not worth the hassle, and the residual value of your car is hammered by the fact that it's been serviced outside the country. With Canadian-spec cars it's probably even worse because no-one wants the daylight running lights or the metric odometer and speedometer.