Can I just host dhcp in any public network?

I'm not sure where else to ask this. :p

Im learning in school about this kind of stuff, and my teacher told me basically in a network if you have a windows server (installed on a vm on a laptop f.e.) on you can host dhcp and nothing would prevent you from doing it, so if I am connected to a public network for example in a station or airport can I just host dhcp and deny devices connected acces to internet? not that I want to do this, I just wonder.