I have instructed hundreds of people in shootng revolvers and helped many of them choose their first pistol. For many, it was going to be their first duty weapon. I have also been a shooter for over 40 years. I have arrived at a set of recommendations that fit all prospective buyers of handguns, I don't care if you plan to own a Glock, a Colt Single Action Army, or a Smith double action 500.
Your first gun should be a Model 10 38 Special double action revolver. Used ones are available at reasonable prices, Smith still offers them new. Have an instructor teach you double action shooting with standard pressure ammo (i.e. round nose lead is the most common). Become proficient at double action. Once you understand double action shooting with a revolver it is far easier to transition to different types of pistols. Plus you will have one of the best guns ever made in your battery.
I was too smart to listen to this advice when I started shooting (you didn't think I was smart enough to hink it up myself, did you? ;>} ). I did not do well for a couple of years. I then had to un-learn all my bad habits and rebuild my shooting skills from the basics using this method. Once learned, these skills are easy to maintain with semi-regular practice.