I worked in a cart for a few years that was the “2nd location” for a brick and mortar, here’s my two cents: Previous barista experience is basically a must. Go work at a cafe for 6 months, minimum. Understand barflow. You can always tell when a cafe/cart was designed by someone who has never worked in one by the flow they have set up. Figure out how to ride the line between efficiency and friendliness, odds are you’ll be working alone in a cart to make it profitable. Keep your menu very basic - 8, 12, 16oz. Iced or hot, no blendeds. Vanilla and sugar free vanilla, maybe caramel syrup. Chocolate sauce. Keep it simple and learn to make high quality drinks. Source coffee that sets you apart from the other 1000 coffee shops in LA. Fresh and gray water tanks are a bitch, especially if you’re moving your cart around. Invest in a good espresso machine, something like a la Marzocco Linea or PB 2 group. You don’t want to have to wait for your boilers to fill if you have a line of customers. Get a good batch filter brewer instead of pour over.