Hi Karsten,
Like you i'm very very new to construct 2 as i have zero programming knowledge.
What i did as suggested by the helpful peeps in this forum is that do some tutorials first and you will be surprised by how much you will learn.
For me i went through the tutorials first then i went and study the multiple different templates which comes together with construct 2, once i have decided on what type of game i wanna make i started and work on it.
And as suggested by the peeps here, try and start off do some development for your game, if you do run into problems, so take a screenshot or post your capx to show that you are trying and you would like to make this work and help will surely come.
And keep reading the forums, as some peeps will ask the same questions as you will once your development is underway, then download the different capx files which is often posted here. You can refer to them and add them into your game.