Where can I find a mentor to help me take my business to the next level ?

Let me start by saying that I agree with Mark. You must separate the search for investor(s) and a mentor. The terms have been harsh because you are currently asking the investor to take all the risk while you come along for the ride. The way your describe it the investor must put their capital at risk then (mentor, i.e. tell you how to run the business) while you provide presumed sweat equity.

My second observation is that you say you have sales. What are your current profit margins? What is the competitive landscape? Other marijuana sellers in your area? Do you have a differentiator? You should be growing and selling as fast as you can with the resources you have and putting every dollar into a down payment on the land. When the down payment is above 20% you should be able to find at least a hard money lender.

If you can't grow doing the above. I recommend that you keep your lic. and withdraw until you can draw up a business plan and have it vetted by several potential mentors. Then finalize the plan and march forward.

Alternatively sell the license.

First things first I'd say to get very clear are you looking for a "business partner" or are you looking for a "mentor." Two different things.

If in the US there's non-profits, incubators, Etc. to find mentors.

www.score.org is a free service for US citizens and I would start there.

Keep in mind that your product is marijuana so I would request a mentor in the states it's been legalized. I would look into the community for marijuana and see what business networks exist for the product. Hope this helps.