It's my first pok game too ;) There's no difference betwen the cartridge and the piracy copy. you can just download it from HShop. Cool game for the first time. Learn the mechanics, then dig into guides: shines, pairing, side quests after the plot... There's a lot of content!

Then you can go to the Ultra sun/mon rubin...or Black/White2–the best parts in my opinion

You get an uncomfortable amount of pokemon as gifts pretty early on and they make the game way easier than it already is. Try to experiment with mons!

You can try to play with Nazlok Challenge. It's some add rules in game ;) Also you can take all Mistery's Gift Pok! Just find instr in the internet... and enjoy (˘•°)