garrus74: First off, the tutorial is there, it's just hidden in the menu that has your inventory, alchemy, character info etc. , and when you encounter things for the first time in the game, interactive messages pop up explaining how things work. I think you need to enable the pop-ups in the settings, but the full tutorial is always accessible through the menu.
Imho, Witcher 2 was more difficult if you jumped straight in than TW3, so if you completed TW2 on a certain difficulty level, just try enabling the same here.
Finally, TW3 has nice hints regarding the difficulty of a quest/monster fight: it could be that you ran into quests that are just impossible to complete given your current level. Try going for quests highlighted in green and avoid monsters that have skulls over health bars, and you should be just fine.
This is a ``parallel'' game <garrus74>, so the best way to play this game is traveling, arriving to towns and getting missions. As long you complete those missions one goes learning on the fly. Just my opinion about how to play this game.