First decide what you want to do with it.
Target shoot (Static at the line) or Action Shoot (Holster and movement)
Then the choice is between Striker fired / Polymer or Metal.
Striker fired options:
Glock 17
S&W M&P
Sig P320
Metal
CZ 75b
budget 1911 platform
Beretta 92
The reason I put those up is there are a TON of accessories readily available (mags, holsters, sights, grips, etc) as well as a TON of online resources (reviews, training hints, articles, technical stuff) available for these firearms.
I suggest you start with one of these widely used 'classic' pistols and go from there. No need to get too fancy or spend too much $$$ until you have some experience and know which way you are headed.
My first was a G17 and second was a CZ 75b. Many thousands of rounds through both, I still shoot them regularly and love em!