American Dream Achievement
GTA Online: Own an Apartment, Garage and an Insured Vehicle.
During your time on GTA Online, you will need complete various jobs and activities in order to save enough money to buy an apartment, garage and an insured vehicle. Near the beginning of your Online experience, Simeon will tell you to grab a vehicle and bring it to the nearest Los Santos Customs shop. Here, you can respray and insure the vehicle for free, because he is covering the cost.
As for the apartment and garage, you must be at least a Rank 5 before you can purchase property. Once you are of rank and have enough money, pull up your in-game cellphone and check the real estate advert, "Dynasty 8" on home page of the Internet. Find an apartment with an attached garage that is both affordable and suits your needs, then purchase it through the website. The achievement will unlock immediately after purchasing the apartment and garage if you still own your insured vehicle.
Many people have reported that if you try to buy an apartment or garage through the real estate signs on the actual property, the achievement will not unlock. So make sure you do it through the Internet. A big thanks to Just Blaze for confirmation on this!