What applies to you at the next junction?

You answered correctly with "turn left" and "turn right" as the valid options at the next junction.

According to German traffic rules, when you see a junction sign like the one shown (a yellow sign indicating directions), it informs you about the possible directions you can take. In this case, the sign shows that you can either turn left or right but cannot continue straight. This is because the road ahead does not continue straight through the junction.

The additional blue sign indicates that the upcoming road is a motorway entrance (Autobahn), and you must be prepared to turn onto that road or take another direction as allowed.

Therefore, the rule is: when approaching a junction with signs clearly showing available directions, you must follow those directions. Here, driving straight ahead is not allowed or possible, so only turning left or right applies.

Your understanding covers this rule correctly.