When a photographer takes my pictures who owns the rights to the photos?

This depends on a few different things. In general terms the photographer owns all rights to the images they create.

There are various laws about what uses a photographer can make of street shots. Some localities require that any identifiable persons sign a release if the image is used for other than news or artistic presentation.

Model releases are generally required for commercial use.

Under contract or work for hire scenariOS the images belong to the party that hired the photographer.

So specific circumstances and laws would apply depending on your particular case.