soises says:
... a cosy dark near future setting (Shadowrun) ...
I don't know that I have ever heard Shadowrun described as 'cosy' before. :)
soises says:
... Neverwhere (all time great) ...
Agreed.
soises says:
... I never came in contact with the PbtA system. ...
OK, we can teach you what you need. There are some hurdles to get over with your mentioned previous realms of experience, many/most of the systems you list are rather mechanics first, and that is what I find to trip up new PbtA players the most.
PbtA is always
Fiction First, you always first look to the fiction and only then worry about what rolls may be needed. If you ever find yourself stuck for understanding what the outcomes of a Move mean, remember that they are always based on the fiction that came before, so they should be clear in the context of what is happening in the scene. If the outcomes don't make sense, then the Move probably did not apply in the situation and should not be used.
This will make more sense as you read the Moves and Mechanics, but don't hesitate to ask questions if anything confuses you, we may point you to a different page of the book for answers (in PbP it is either that or we type them up and you have to read them anyway:) since often one needs to understand other concepts before the current one makes sense, and often both rely on each other so for both you have to have read the other first... which is a paradox.
soises says:
... it is very important that we don't "just" tell a good story, but also are able to change things ...
That is a large part of most characters' motivation in the game, the desire to change the world to better fit how they want it to be. See the Factions (and Status) for the most direct way you can do that.
soises says:
... and (at least sometimes) feel like heroes. ...
Hopefully we can give you that, but this not a game about heroes. Take a look at the description of the Power Circle in Chapter 2, and compare that to Dresden and Dresden Files; also pay attention to the Corruption mechanic, you are not always playing 'the good guys', though you should still try.
soises says:
... Without rules knowledge that gets - in my experience - very hard pretty soon.
I am not sure what this means. If it is important, then please elaborate.