Yes, if you have an open work permit in Canada, you are generally allowed to engage in various types of employment, including starting and operating a business like a grocery store or an online service. An open work permit does not restrict the type of business activities you can undertake.
As for your spouse on a dependent open work permit, they too are allowed to work, including in a business that you start. However, when employing your spouse, make sure that the employment adheres to all applicable labor laws and standards, such as providing a fair market salary and maintaining proper employment documentation.
Do note that in order to incorporate a business in Canada, you must comply with Canadian residency requirement for directors ->
Directors and officers
If you are able to create a business entity, you may then hire Canadians or Open Work Permit Holders to work for your company including your spouse. However, specific attention needs to be paid before claiming points (by the spouse). For your spouse's experience in your business to be eligible for points, it must be paid, authorized, and well-documented. The Job Offer must be considered "valid" before she can claim any points. The validity depends on the immigration program that your spouse is choosing. Read on what constitutes a valid job offer:
Offer of employment – Skilled immigrants (Express Entry) - Canada.ca
Other aspects to consider are your Principal Foreign Worker requirements for spousal open work permit application.
I suggest that you speak to a good RCIC or Lawyer who can help you formulate a strategy.
