How can an united states citizen legally obtain real estate…

You do not have to be a citizen or permanent resident to own property.

However, to own and operate a general store and live here, you must have immigration status.

There are a variety of categories of immigrants accepted in Canada.

From your brief description, it sounds like you may want to look at qualifying as an economic immigrant. Detailed information on how to qualify as an investor, entrepreneur or self-employed person can be found at the following link:

http://www.cic.gc.ca/english/immigrate/business/index.asp

The category that seems most relevant to you given what you have mentioned is the entrepreneur category. To quote the language on the above website,

"The Entrepreneur Program seeks to attract experienced business persons who will own and actively manage businesses in Canada that contribute to the economy and create jobs. Entrepreneurs must:

• show that they have business experience
• have a minimum net worth of C$300,000 that was obtained legally and
• respect the conditions for entrepreneurs after they arrive in Canada. "

Detailed information on the entrepreneur program can be found at:

http://www.cic.gc.ca/english/immigrate/business/entrepreneurs/index.asp

Hope this gives you a good starting point.

Kindly accept so that I can be credited for the above assistance.