I am 57yrs old, office manager, 28 years with the company in Ontario, canada. If there is laid off or termination of employment, how many weeks notice? And How many weeks severance am I entitled?

At common law, your employer can give you a combination of severance pay and notice of termination, at its discretion. Given your age of 57, position as an office manager, and 28 years of service, you are entitled to between 18 and 24 months' notice of termination or severance pay (http://www.severancepaycalculator.com/).