I have shot three indoor and one outdoor GSSF match. It is suitable for all ages and skill levels as long as you follow the rules and practice safe gun handling. Go to the GSSF website and you can find out everything about it.
The basics are you use mostly standard glocks and start with the gun facing down range and then engage a series of cardboard or steel targets at known distances. Time and accuracy count.
I have been shooting IDPA for about six months it is tailored towards CCw in regards to firearms and scenarios. It involves a good bit of gun handling and reloading and moving and shooting. The IDPA website will give you a lot of information. There are a lot of clubs and ranges having IDPA (and IPSC) matches, you may have one close to you.
I have never shot IPSC or similar and do not know any details but I am sure they also will have an informative website.
http://www.gssfonline.com/
http://www.idpa.com/
http://www.ipsc.org/