Pixelmon Mod

Hi there I'm about to purchase minecraft because after watching so many videos I really want to play pixelmon. I'm pretty sure I know how to do it by downloading the latest pixelmon mod and going through the installation process. My question is though I would like it to be a world with random trainers, gym battles, shinys and boss Pokemon like I've seen on the videos I've watched. I'm only planning single player to start off so I'm not sure with just the latest pixelmon mod what it will offer? To have it how I want it can I get some help or advice how to add these things as I'm a noob with this sort of game. Hope this makes some sense and you can see I want to play but those features would increase my enjoyment factor for single player. Thanks in advance Brad.

As soon as you install Pixelmon and launch a world in singleplayer, you will have all of those. Towns will have pokecenters, pokemarts, NPCs, and generally, you will find bosses, legendaries, shinies, NPC traders, NPC trainers, etc.