As I understand it, it works like this:
At level 2, the player can select an archetype (provided he has the required ability scores) and receives the dedication feat for the archetype for free.
Then the player receives an archetype feat (of the choosen Archetype) for free every even level (4,6,8 ..).
Did I miss something?
Maybe some wiser GMs can explain that (as simple as possible ^^)