How to get to Fontaine

There is no need to manually go all the way to Fontaine! There will be some waypoints automatically unlocked in/near Fontaine if you have completed "Prologue: Act III - Song of the Dragon and Freedom" Archon quest! (Mondstadt Archon quest)

If using the Waypoint in the Realm of Farakhert you can take a waverider to the Romaritime Harbor Statue of the 7 using the path as shown here.