Heading to Seoul soon! Looking for some must-try K-beauty and skincare recommendations. Any suggestions?

Hello everyone! I'm Dan, from China. I'm going to Seoul next month for a trip, and the most exciting part is finally getting to experience the legendary K-beauty. I usually follow Korean skincare closely, but I've never had the chance to try it out in person. Now that I'm finally going, I can barely contain my excitement!

My main question is, besides browsing skincare stores and buying products, are there any beauty experiences or skincare treatments you'd particularly recommend? For example, things like skin management, which isn't as common in China. My skin is on the oily side with some acne scars, and I'm wondering if professional treatments there could help. Also, I've heard that certain areas in Seoul are particularly good for these experiences – can anyone share some insights?

Additionally, I'd like to ask for advice: should I book appointments in advance before going to clinics or beauty salons? Will language be an issue? My English is okay, but my Korean is really not great. I'm especially eager to hear advice from fellow ladies who have had similar experiences! Looking forward to your replies~