If redshift is not already installed on your system, you can probably do so using your package manager. Installation may create a configuration file, probaby at ~/.config/redshift.conf, but you might have to do this yourself, at that same location. Below is a simple config file for someone located in Ottawa, Canada. Note that the negative longitude indicates the western hemisphere.
Restart your system and Redshift should start on its own.
[redshift]
temp-day=5700
temp-night=3600
adjustment-method=randr
location-provider=manual
[manual]
lat=45.5
lon=-75.6