If this is your first time exploring via ferrata in the Dolomites then it is highly advisable to do so with a guide. Even if you have climbed before, having someone that knows the route on your first venture out is valuable.
Pay careful attention to which route you choose. During the summer months the rocks get busy, and so it is not always possible to head back down the way you have come if you decide not to finish the climb.
Helmets and harnesses are available to rent from specialist shops throughout Cortina d'Ampezzo. Even if the route you are on has low exposure you should always wear a helmet.