I love this movie. It is absolutely hilarious. I am an adult.
Unless you want to talk to your child about odd adult acts, or what Deadpool meant when he said "right down Main Street," I would not buy this video for a small child (Ant-man, Captain America, X-Men and other superhero movies are better in this instance).
Teenagers would probably think you were the coolest if you bought this for them. Being they have probably heard worse language on the school bus, seen more gore from their video games (Thank God for gorey video games), and have all claimed to do the deed (even though most of them haven't).
In other words, don't just buy this for any kids younger than 13 years old because it's a superhero movie. It ain't your normal superhero movie.