To get a ticker you must meet the following criteria:
1. You must be a member for 20 days. And it is to the hour. So if you joined at 7 pm then you will recieve your edit signature option on the 20th day around 7pm that night.
2. You must post at least 20 times.
On the 20th day under your User CP you will have an "edit signature" tab. That is where you will add your ticker. Then it will add it to every post automatically. (unless you tell it not to.)
You can see what date you joined by looking at your profile. It will also tell you how many posts you have.
Hope this helps.