Free parking outside Berlin?

Hello! I am driving from copenhagen to berlin this summer, and want to park my car somewhere free and take the public transportation to prenzlauerberg, where we are staying. Would be great to be able to take the S or U bahn, and not having to switch lines, so i wondered if a station like Pankow U+S would be a good choice since, there is a direct line to eberswalder str station? Does anyone know, if there is free parking there, and if its possible to find a spot?

I saw a lot of people recommending the "park and ride", but someone on reddit said it is only free for 24 hours, which doesn't work for me. Does anyone know, if this is true?

If someone has a better tip, please let me know!

Thank you in advance?