@MLE_online not a legal expert. there are certain limitations. but just something being property doesn't make it illegal to enter. there's the concept of Besitzstörung "disruption of property" for example. you're not allowed to inhibit someone's use of their property. say by blocking access to a driveway with a car. and yes intruding on their privacy in their home (this includes your landlord; they cannot enter your home without permission).
so it's not that everything that would be covered by "trespassing" in places where that concept exists would automatically be legal here, but rather that that legal concept does not exist here. other legal constructions do, so some specific cases of what elsewhere might be "trespassing" might be illegal, though some of those might also be additionally covered under other legal concepts anyway.