Hey there!
Actually Terminal 1 and 2 are approximately a few minutes away. To be honest with you i did it last time quite a while ago but I am sure the road has not changed There is a taxi rank just out of the arrival hall and the free shuttle seems to be leaving every 7 minutes. it really can not be more than a 7-8 minutes ride by Shuttle. both depart from the same area (you will see it when going out from the hall).
Just make sure you have the boarding pass to Easyjet and therefore just need to drop off your luggage. I am from Sicily, do you already know your itinerary? enjoy your trip! if you are lucky enough on approach you will fly past the Etna Volcano, the highest in Europe. I took a spectacular flight last month and we flew all around it during a very rare and clear day on the top! Amazing.