Search the relevant forum, there's loads of answers to similar questions already.
Re alcohol, you'll need them to be exported via a bonded warehouse over there otherwise you'll end up paying alcohol duty at both ends. No idea about foodstuffs from Africa, but I imagine testing of some sort will be mandatory.
Selling alcohol requires a permit in canton Zürich, issued by the commune (Zürich city) (you can't allow consumption on your premises). That seems to require you to register with the cantonal food lab (supervising body), the LebensMittelKontrolle .
Regulations for selling as a retailer will probably differ from selling to retailers.