What to do next after H1B laid off?

I have a H1B and sounds like I'm next on the laid off list. I know that I need to return to Canada as my company will certainly notify USCIS as my status. In the meantime, I'm looking for work both in US and Canada. I need some time to sell my house in US, pack up etc. Should I apply for B1 visa? Can I do this myself?

You can either re-enter as a B-2 visitor or file for a change of status using form I-539, but to use the form the instructions say you need to give them 45 days, plus it also costs $320 to file. It's usually quicker just to leave and re-enter.

I have to say if you're sure you're going to get laid off you might as well start packing now, you are allowed a "reasonable" amount of time to leave, which USCIS interpret as ten days.

If it were me, I'd pack up, take as much stuff as I could then go back and tell them at the POE you're in the process of moving back and need to make another trip to fetch everything.

You'll need CBSA forms B4 and B4A to bring your stuff back duty-free.