There are 2 typ of mission dziecko. Standard missions and Critical missions.
Standard missions are missions you can always do. There are 7 types or so, can't really remember them. There missions will be available after you completeled the Intro missions.
Critical mission are, mostly, storyline releated missions (besides the intro missions). These missions gives us inside in the upcoming event or the cinamatic.
Since you're new, you missed a lot of old cricital mission. I'm not sure, but I don't think you will get mission which involves the assassin, for example.
