Good for you and your brother! As you can see, there is a great deal of information on this board as well as a lot of folks who are willing to share their experiences. I think that once you and your brother attend a CHL class, your questions will definitely get answers. Fee free to ask here but do not feel too overwhelmed, there were about 50,000 people alone in Texas who applied for their CHL since last January!!! Lots o' people who are/were just in your shoes (as a LOT of us were at one time).
Just like any new endeavor there will always be a feeling of "what did I get myself into"... perfectly natural. Just keep an open mind. The class itself is designed to expose you to the laws that govern concealed carry in Texas. My wife recently attended her CHL class and found it to be very informative. She had at least 7 other women there (awesome) and that made her feel even more comfortable.
Most importantly the knowledge gained will only serve you best if you make learning a continual part of your daily outlook. You don't have to go Rambo or anything but every skill improves with practice.
Check out the "New to CHL" and "Waiting Room" threads as they are full of people who share common 'first timer' feelins' ....most of them are "man, when is it going to be my turn to get my plastic!"
Again congrats and welcome to you and your brother....and good on your father!!!
Rok