All you need is a respectable sized table, some chairs, a cooler with water and biodegradable cups. Don't forget to set up a banner that says LEMONADE, accompanied by price per cup. Arrange your fees based on ingredients expenditure and by setting a decent profit.
This special lemonade is made from granulated sugar, squeezed lemons and chilled water. Make sure you experiment to get just the right twist of flavours prior to launching your enterprise.
Lawsuits are more than common these days, so liability insurance can be another issue. Consult your solicitor about whether or not you need it. No matter how ridiculous the hypothetical, anything is possible. Such potential incidents that need to be dealt with may include a customer's allergic reaction to lemons, or customers walking into your stand and bringing the whole thing down upon themselves, you and others.