Hello,
how can I get graphic like in games like FireWatch, Life Is Strange, Walking Dead, …?
Can I get graphic like that with Substances and a filter or something like that? I’m not very good at hand painting and I don’t have money to pay for a graphic-designer ^^
So any ideas or tipps to get graphic like that? 
The common thing those three have is painted textures (because otherwise, they have pretty different art styles).
So, since you ruled actually making painted textures properly, Google for filters for whatever software you have available.
You can do this with same result in Photoshop(or similar tools) or shaders. .
Shaders is like Photoshop actions in run time.
Thank you, that sounds good. Can you recommend a shader for this?