What is the right course of action here?

You are required to allow both the yellow car and the blue truck to pass first because of right-of-way rules at this intersection.

The yellow car is coming from the right, so it has the right of way. According to the "priority to the right" rule, vehicles approaching from the right have priority unless otherwise indicated.

The blue truck is already on the main road, indicated by the "no entry" sign on your side, which means you must yield to it as well when turning left or going straight.

You must wait for both vehicles to pass before you proceed safely. This ensures smooth, lawful traffic flow and prevents collisions.