Without status in USA trying to go to Canada

[Altrueno]

Hello I need some advice, Im in USA without legal status, I enter to USA with tourist visa 7 years ago with my wife and my 1 year old son, now I have two more kids that born here, Im from Mexico, and I finish my studies in Law there, but for my condition I can't work, so I start a business 5 years ago, and is dong good but all limitations for not be legal, and also I like back to work in my profession, so I thinking move to Canada, I was reading some topics here and somebody comment that if you apply for any temporal status like study or work, you must be legally accept in USA for at least 1 year, but if you apply for a PR it doesn't matter, so here are my questions, Can I apply for a PR with my family in my current situation in USA? if so, Can be for the express entrance or different program? Can I use for make more points my profession even if I don't practice 7 years ago? should be better use my experience like enterprise? Can we apply from USA or we have to go to Mexico? Well I think thats it for the moment, we don't have any legal problem and my company is in good status, thanks hope somebody can help me