You have not mentioned what kind of organization you are working with - I mean private/public/government. Anyway, after approval from management, you first need to decide on the requirements (simple lunch or breakfast/tea/coffee, etc.). Prepare the scope of services and then invite quotes from canteen operators/caterers. Also, plan for procuring crockery, utensils, cooking gas, stove, insect catchers, etc., as they may need to be provided by the company to the caterers.
Assuming that you have the proper infrastructure (building with furniture), upon finalizing the party, you can start the canteen facility. Monthly coupons can be distributed, and recovery from salaries can be made. You can also form a canteen committee to oversee its management. Once it is operational, there are numerous things that could be done for further improvement.
Regards,
Priyanka