If my first node and second node depend on two messages, how should I deal with it? The first node arrives and it is not triggered immediately. I will only be triggered when the second message tells me that it can be triggered.
To wait for both messages to arrive you need to split the flow into 2 parallel paths and let each path wait for a message using a message intermediate catch event. Their outgoing flows should converge with a parallel join gateway to make the flow waits until both paths have been completed.
Something like this:
Hope this helps