^You need a garage or apartment w/ garage combo in order to store more than one vehicle. You can still buy a vehicle but if you don't have a place to store them, you will only have one vehicle and you will need to replace it if you want a new vehicle. When
you get high enough, you will get an option on your phone called "Pegasus". With this, you can then proceed to buy boats, planes, helicopters, Tanks, and other vehicles from Warstock Cache and Carry. When you want one, simply call Pegasus and select the vehicle
you want. It will be delivered to you at a "storage area" on the map. Drive to it and you can then drive/fly the vehicle. Having a garage will allow access to more than one vehicle and you will also be able to view your collection.