Oh boy, don’t listen to me, but a cell phone and motor club card and number. Cash, debit and credit cards. I like to have a few cans of coke in the car and some extra smokes, and a good book depending on how long I have to wait for a tow.
Most break downs are from common items like tires, belts, hoses, etc. and only major stuff on one like I drive every day. So doing the preventive maintenance will go a long way. As far as what to carry I’m with the others. Basic tools such as metric and SAE sockets and wrenches, pliers, screw drivers, flashlight for sure, and a breaker bar of some type to loosen lug nuts. I also carry a spare belt, oil, and some other fluids and parts such as fuses that help rule out simple problems or help make simple temporary repairs. I’ve also found it helpful to have various phone numbers such as taxi, repair shops, etc. in my phone.