Location: We're still at the soccer pitch.
Panel 1: Duncan starts rambling about his future by listing the attributes Lynn has assigned him. He's interested in business stuff (sic), sports, travel and communications.
Panel 2: April and Eva speculated on possible careers for him. April's suggestion of the obsolete position "travel agent" is Lynn's failed way of trying to make her sensible while Eva's grandiose design of turning him into Don King is meant to show her as a flighty teenager. In any event, Duncan has no idea what he'll do.
Panel 3: After all, as he says, there's always a open door to a better future. This optimistic ramble sets up the stupid punchline.
Panel 4: That's because April can't resist dropping a baffling clanger about remembering to let go of the knob. This is a mature person?? She can't even make a pun that makes sense.
Hypothesis: The point of this sequence is to depict the final dissolution of her silly, weak-ass garage band. They can't be bothered wasting their lives playing headache music! They're on the way to Now Town, baby! "Now Town", of course, being defined as a dull, soul-destroying job they'll be doing ten years after they're dead.