To get ecs you can either do jobs that give free ecs once jobs are done. Granted the % of drops isn't high. You can also go to the nurse & buy packages that gives you ecs. As for avis you can do hunts to try and win avis. Now days hunt avis you just need a key to unlock it. Keys can be traded for with other players. Take note to be careful when trading hun. Maybe ask for a key 1st. When you go to the nurse tho it will show you your current avi once you scroll down. You can click under the avi & scroll through avis you can buy with ecs hun.