coffee cart catering

i started off with the idea of a coffee cart that i would need generators and it would be quite expensive. i think it would be wiser to consider the idea of a catering service where i would require the place im catering provide the power source needed for a coffee cart.

so im wondering if anyone knows if i would still be required to provide my own hot water and handwashing sinks? like since id be at an indoor event where theres most likely sinks nearby does that not count?