Arizona has very few restrictions on firearms relative to many other states. No permit is required to carry a loaded handgun but the gun or at least the holster it is carried in must be visible by law. To avoid any potential legal hassle, it is wise to ensure that the entire firearm is plainly visible. You cannot OC into government or private buildings and events that are posted "No Weapons" and if asked to leave you must comply. K-12 schools as well as most college campuses ban weapons. Bars and restaurants that serve alcohol also prohibit open carry. Many public parks will also be posted so check for signage. Other than that, when you are travelling whether in a car or on foot you can carry however you like as long as the gun stays visible. Common sense of course is recommended. If you are carrying a handgun, wear it in a holster and don't take it out in a grocery store to show your friends. If for some reason you decide to carry a long gun (which is rare unless people are going hunting or to the range), it is better to have it on a sling over your shoulder vs. in your hands to avoid a disturbance. That being said, carry away as there really are few restrictions on firearms in Arizona relative to other states.