Does every campaign have its own tracking code?

Simply put, no.

When you subscribe to a plan, you get an individual Customer ID, which will show in your tracking code as well. Regardless of the number of campaigns you've created, they will all run by the same tracking code.

Therefore, you only need to implement the tracking code once for your campaigns to show on your website.

Also, if you have more than one website, the tracking code will still be the same. Remember to implement the tracking code once at each website and you'll be good to go.

Below is what a tracking code looks like and, as you can see, it contains a unique Customer ID.