Turbo, if you have had no training in firearms I would suggest the basic pistol class offered by the NRA. The site you listed is an advanced training company and unless you have basic skills they may not allow you to take the classes. The group that I teach with has various instructors with differing skill sets but we all agree that all our students have basic class before going on to tactical classes. You can find NRA instructors in you area at their website. Good luck and good shooting.
Teach your children to tell an adult if they are at someone else's home and while playing find a gun. Don't touch, tell an adult. That is what the NRA Eddie Eagle program teaches to children to young to teach firearm safety. As soon as they are mature enough take the curiosity out of equation and teach them how a gun works, that it is not a toy, and that if they have an interest, take them to a class.