Great advice. I'll reinforce with:
When starting out, have an experienced shooter guide you for a little while...it really helps to catch poor shooting procedures before they become habits. I had no idea what a "sight picture" was when I got started.
When shooting, have fun, be safe, and concentrate on doing it by the numbers...improvement and skill are more a factor of sheer repetition than inherent "talent." I spent way too much time early on beating myself up for "terrible groups." As I shot more and more, concentrating on consistence, not groups, it just "happened" to get much, much better.
Make your gun selection decision based on your needs, abilities and preferences, mixed with a little dose of friendly input. [As you can see on this site, there are endless discussions regarding "revolvers vs. autos," and "the 'best' calibers."] After a little practice, input from shooters...you're the one that has to shoot the thing, get what you like. I fell for the idea that "big is always better" when I purchased my first, a Ruger .41 mag. Let me tell you, that was no way to get started!
Be safe, relax, determine your needs and desires for gun purchases, and shoot often.