What should I prepare for my May Day trip to Qingdao?

Go with the group. In that case, you should bring your teeth, ID card, wallet, camera, mobile phone charger, wet wipes, laxatives (or berberine) and a long-sleeved sweatshirt instead of short sleeves. You can't put it on yet. It's cold in the morning and evening, so you can take a thin coat. Put these things in the suitcase and prepare a carry-on bag.