>Is it possible and are the two series somehow related?.....

They said there's no connection between the two. Don't wanna repeat ourselves kinda thing. So you can enjoy it, it's very enjoyable and addictive and well made. I couldn't stop binge watching honestly. It's easier to watch (on the surface at least) and you can go on r/1899 for more help.
Creators said 1899 is both for fans of Dark and casual viewers (in RT interview) maybe that's the reason. I personally know some people who haven't enjoyed first couple episodes of Dark and enjoyed 1899 very much.
But in the end you should give it a watch yourself to make sure (and please watch it in first 28 days, it's what Netflix really care about, and imo start with 1899).