First Pokemon game ever! I'd recommend getting Platinum instead if you can find it, it's got a bit more variation in Pokemon and a few changes that make for a more fun playthrough. If this is your first time playing these games, I'd definitely recommend Chimchar unless you're a big Ponyta fan (That's the only other fire type besides Flareon I guess). All the starters are super cool in my opinion, although Piplup's early game moveset is kind of lacking. Also be prepared for grinding late game towards the champion (Best champion ever btw). Overall a fun story in a cool region with a bunch of amazing pokemon introduced for you to use. Some of my favorites are Garchomp, Floatzel, Luxray, Staraptor, and Gengar (I know he's not from Gen 4 but you can find him in the Old Chatuau and he's one of the best ghost types ever, just keep in mind you'll need to trade him to evolve him, so make sure you have another compatible Gen 4 game to do it with.)