。
Are the travel preparations ready?
Literal
Trip [possessive-の] preparation [topic-は] done [question-か]?
できていますか uses ~ている with できる (to be completed/ready) — asking about the current state of readiness. Three near-synonyms can express 'preparations are done' with slightly different nuances: 済む (properly wrapped up), 終わる (finished), できる (ready and in place). Picking between them is a matter of fine emphasis.