Welcome to RCH! That is a very nice collection of F1 cars there.
100% honestly here, the 600 is not a great first helicopter. A nitro 600 even more so. They are more stable, but they are also way more expensive and dangerous. If you can swing a 450 with a flybarless head and get a good gyro like the Ikon with bailout, it may help save you some money. Instead of a crash costing $300, it's only going to cost $80 on a 450 (light crash that is).
With that said though, I know some want to start off larger because they are, in fact, more stable in the air. If this is you, ignore what I posted above lol.
Collective pitch or CCPM helicopters are not stable and getting them stable, especially a flybar helicopter, is very difficult and takes hours and hours of fine tuning to get there. Even then, it will not hover hands off. You always have to give these helicopters input to keep them where you want them. Think of it as a marble on a sheet of glass. If you place a marble on a nice flat sheet of glass on the ground, the marble is just going to sit there. But once you pick up that glass (taking off with the heli) it is going to start to wonder around and you are going to have to move the glass around (stick on a Tx) to keep that marble in the center (where you want it).
6ch helicopters are hard to fly regardless. Even in the simulator. Speaking of that, we are going to be doing Simulator Sunday tonight at 1900 CST if you are interested in joining, I know its kind of late for you. But sim time, an hour a day and don't treat it like a game, treat it as if every crash is going to cost you $300. It takes time, some learn faster than others, but we are always here to help out if and when you need it. You just have to post up. Practice, that is the name of the game in the beginning.