I don't have a Mustang RAK decoder ring. If when you turn the key on, you hear stuff the FP prime, etc, that suggests the computer works. If the car runs, the computer works.
You can use a timing light to observe your timing advance, if you wonder if you are advancing. If someone removed the SPOUT connector, you will not have timing advance.
Here is a write up by Tim about setting timing (If that is what you want to do). Click on "Links" on the left side and then click on the timing article.
No problem. Just post whatever questions you have, as clearly as you can, and everyone will help you out as much as they can.
I bet you might even have a little bit of a hard time 'searching' the threads in here because of the language barrier, so just ask whatever comes to mind.