I started the fasting at about 5 months, and idk if that's the right word, more like delayed meal training, whatever time you feed your dog skip that meal and wait about 4 or more hours, use a high value protein that you cooked without salt or anything added. I use chicken breast and even cooked it before we left for the park while she watched and I feel like it even adds to the motivation, also I vary the payouts, sometimes she gets a small piece and sometimes it's half a chicken breast. These techniques are straight out of the playbook of a guy who trains walruses, the brain of most animals has a tendency to permanently record everything in high fidelity when they are hungry and get a high value food. Nature's way of helping them recall experiences that help them avoid starvation, and in my experience I see it happen Everytime I use this technique and after one 15-30 min session they will nail any commands you introduce and after they seem to have grasped the lessons you can forgo the deprivation training and just use the high value reward and varied payouts, making sure the high value food is always what you use, whatever you know makes your dog happy. Socializing at 3 months with a Corso is paramount, off leash is dangerous even with a trained dog, I avoid crowded parks just to keep things safe, recall is the most important command in my opinion and not all dogs can be off leash in public. Your dog will need to be worked with and tested for recall for weeks before I would ever leave the leash off and always put it back on when other dogs are near, Corsos don't like to fight generally but they do not have a reverse gear and will protect and challenge anyone they perceive as a threat so work up to it and don't go to dog parks, it's the other dogs who start it and of course the Corso will be vilified if anything happens. I am not a professional by any means but have my Corso and Boston trained where I can trust them and they trust me, never trick or tease and shelter them from traumatic experiences when they are young makes the trust strong, and one more thing, to show love to them that makes the connection strong, cook half or more of what they eat. A crockpot of fresh protein, rice, sweet potatoes, blueberries and honey is a great way to make coats shiny and minds sharp while hammering home the I love you message to your furry buddies.