As a general rule, people are not interested in financing a startup. They are interested in financing a real business that has proven upside potential. You have to prove your concept (idea) is valid if you want to attract financing. Without a proven market for your idea, you are considered very high risk which makes it very difficult to attract financing. The few startups that attract money tend to be highly transformational; i.e. they are doing something very different compared to what exists and there is very serious upside potential when they go to market.
Sometimes you can convey low risk without having any customers, but you have to document and show strong interest or commitments for sales do in fact exist. If you have limited resources, then you might target products that people in Tunisia cannot get, but want and you have proof through surveys or other proof points that can be verified. This documentation can be presented to a large supplier outside of Tunisia who is willing to finance a test run to validate your idea. This gets the startup out of conceptual stage (idea only) and into the world of a real business. This is how you can attract financing. You need to find a low-cost entry point where there is proven demand for a willing supplier and you prove to the supplier that you have demand by remitting the wholesale price for the products you sold. Until you do this, it will be difficult to get financing for your startup. There are no short-cuts unless you have something that is very transformational on a large-scale.