Have 3 phase 440v at the street and want to convert to 110v for my camper? What do I need?

An electrician.

Doesn't the power distribution for the building include a 120 V panel?

A transformer will be required. The building may already have a multiple transformers.

The distance/load and where power is measured also plays a role.

It would probably be best to tap into the distribution pint and after power is measured by the utility. This type of service should have a large distribution center where power enters the building where 440 3phase, 208 3 phase and 120 single phase should be available.

I'm just curious but that's an extremley strange configuration. Are you trying to tap off a light pole?

One option is to convert everything in camper to 440 Volt/ 3 Phase?