The short answer: One class can be memorable. A week builds familiarity. A month creates repetition. The useful duration is the one you can attend and recover from.
One class
Use a single drop-in to experience the gym, learn fundamentals, and decide whether you want more. This is enough for a meaningful holiday activity when expectations stay realistic.
One week
A week lets drills feel less unfamiliar and gives you several chances to apply corrections. Choose one or two sessions per day based on your existing training volume.
One month
A month creates more repetition and makes private technical goals easier to revisit. It also makes recovery habits, sleep, hydration, and managing minor soreness more important.
Ten flexible sessions
A flex pass can suit a longer stay with irregular travel days. Consistency still matters, but the pass removes pressure to attend on a fixed daily frequency.
Use current gym information
Prices, schedules, policies, and coach availability can change. Use the current prices and schedule, then use the training planner for the next step.