first port of call

Noun

 * 1)  The first port that a vessel calls in at after the start of a voyage
 * After leaving from Southampton, our first port of call will be Gibraltar.
 * 1)  The first place to go to start a process.
 * When you move to a new country, your first port of call is often the local police.
 * To find the meaning of a word, your first port of call should be a decent dictionary.