Vasa's maiden voyage first destination was Vaxholm, one of many islands in the Stockholm archipelago, to drop of some guests that was on board the ship. The final destination for the ship was the fleet's summer base Älvsnabben, where they would await further orders to sail to the war against Poland.
The 300 soldiers was supposed to go on borad Vasa once the order to set sail for war was made by king Gustavus Adolphus. Together the soldiers would make up two-thirds of Vasa's crew.
You can read more about Vasa's history on our website: https://www.vasamuseet.se/en/explore/vasa-history