In detail, this means:
Vehicles, planes or helicopters will be available in vehicle shops or Hangars in the game.
Weapons will be available in Weapon shops in the game.
Consumables will be available in the Utility Wheel.
Explosives will be available in the Weapon Wheel.
Please note that you will need to complete the mission The Resistance (an early mission in the game) before most of the menus and contents become available.
If you have trouble locating content you should have unlocked, the information in this FAQ might help.