I am level 7 on GTA Online and still haven't been contacted by any characters like Simeon or Lamar to get missions. Is this a glitch or is there something I'm not doing?
In GTA Online, you have to get your missions yourself. There are just a handful of missions where you actually will be contacted. You can call all the NPCs via phone menu -> contacts. In the beginning, you only have simeon and this drug dealing guy in the appartment. When you reach higher levels, you'll unlock new NPCs which also have new missions for you.