Skip,
lots of good info and advice already given.

Everyone has to decide for themselves if protecting themself with lethal force is the right thing for them. Consider how often you visit places that don't allow legal carry (all federal gov't buildings, military bases, courts, bars, schools, amusement parks, etc...the list varies by state) and how you will secure the weapon when you have to leave it in your vehicle. There is liability attached to every bullet that leaves the weapon.

In the class, you will be taught the nuances of the laws but most importantly how to be more aware of your surroundings and to use everything available to avoid a confrontation...including evade and escape. The last thing anyone wants is to be in an altercation (unless you're the type that goes looking for trouble...in which case CCW is not for you). When the weapon is drawn, there must be every intent in the person's mind to put an aggressor down. There is no "set phasers to stun".

But I'll add something else that is equally important but oft overlooked: after you pass your test, background check, etc and get your permit; continue to practice your proficiency.
Just like motorcycling, practice keeps your skills up so they are there when you need them.

btw, the S&W Sigma shoots well (after a bit of trigger work), is inexpensive, reliable and very lightweight for a CCW. But I will add that a smaller more easily concealable weapon will let you carry more often. A small 380 (e.g. Ruger LCP or Taurus TCP...which will kick sharply since it is so small) can be carried with a pocket holster very easily in most trousers or shorts. No worries about long shirts, vests, jackets or "printing". There was a serious run on 380 ammo but lately it is getting easier to find. In fact, my local wally world looked like they had something in almost all the calibers they normally stock.

Final comment. Search the interweb for a CHL forum for your state. Usually lots of good info there including where not to take a class (incorrect paperwork or bad fingerprints are rejected and leads to delays) and often discussion or "case studies" of testing the laws.

good luck.