The gun show guy did not exactly steer you wrong. HP-38 is a good choice for 9mm. SPR GDHP is a abbreviation for Speer Gold Dot Hollow Point bullets and while they are fine, they are expensive (about 20 cents ea.) to target shoot when compared to regular FMJ or less expensive lead.
Like mikld suggests The ABC's is a very good starting point. Amazon has it for Kindle $12.99, and you can borrow it free for Kindle if you are an Amazon Prime member. My wife was certainly surprised when that showed up on her Kindle home page.
I would also get the Speer 14th edition, it has lots of good info on 9mm and loading for automatic pistol. You need to learn about cartridge overall length, case length, de-priming, priming, and crimping. Plus you will need a decent set of calipers and of course a scale.
Take advantage of the wealth of knowledge here in the forum as well by searching. As you go along you will soon see who has the experience and can be trusted for good advice.