If you have enough time, you can visit the border between China and North Korea in Tumen and Zhengjue Temple in Dunhua (the largest nun in Asia, I have been to many cities, and the scale of Zhengjue Temple is larger than that I have ever seen).
If you play in Yanji, I can give you some advice:
Shopping malls: the prices of department stores and international trade are relatively expensive, and each city is similar. There are four distinctive shopping malls in Yanji that are worth recommending: Chengbao, Women's World (also called Fashion Shopping Plaza), Aide Department Store and New Underground Shopping Mall. These four places mainly deal in Hanbok and small articles, especially Chengbao Building. Many clothes are imported, and you can also see many Hanbok small gifts and the like, and they are all near the West Market. You can directly visit these four shopping malls without changing places.
If you want to buy some trinkets, you can go to Lido Shopping Mall opposite the West Market. There are also some Korean trinkets that girls prefer. If you want to buy some special products, you can buy them in the western market, such as beef tendon and fish, which is also very good and convenient for shopping.
As for food. I have more research. There are only a few ethnic snacks that Yanbian can eat.
Cold noodles-Jindalai's cold noodles are famous, but they don't feel very good now. I think three thousand Li cold noodles are the best. You can see them in the alley south of Chengbao Building. The price is about per person 15 yuan.
Dog meat, the dog meat hotpot in Meihua Dog Meat Restaurant is very famous in Yanbian. There are two shops. Basically, I told the taxi driver that I would take you to plum blossom dog meat. You can basically take a taxi for 5 yuan.
Korean BBQ, when I come to Yanji, I think I must go to Oriental BBQ City. The price is reasonable, mainly because the service attitude is very ethnic. There are many branches in the Oriental Barbecue. Personally, I think the best food is the oriental barbecue on Niushi Street and the oriental barbecue near Henan Bridge.
If you like mutton kebabs, Cheng Chuan, Mao Feng is also good, and the service attitude is very good. The radish and pickles given in it are delicious, but now the price seems to be not cheap, and everyone can't eat anything good for 50 yuan.
If I have time, I think it's also good to go to Grandma Yuan's rice bag. Sitting cross-legged in front of a small kang table, drinking some glacier beer and eating rice bags with rich Korean culture, I especially like it. The sauce and rice in their rice bag are very good. Fried Spanish mackerel, fried vegetables and pork belly with spicy cabbage are all delicious.
There is also a state-wide bibimbap, near Park Bridge. If you are in the west market, you can walk there.
Hotel? Yanji has a good environment and there is nothing particularly affordable. There is a Home Inn near the railway station. I heard it's ok, about 160 standard room. Other hotels are basically 3-or 4-star hotels, so there is nothing to recommend. Last time my classmates came to Yanji, the price was about 130, but that's it. That's it. There is a small hotel called Jiangnan in the alley to the west of the park primary school near Yanda, and the environment is also good. I think it's 40 yuan, but there is no separate bathroom.
In fact, going to Yanji is mainly about eating something and climbing Maoer Mountain. If you have time, it is also good to visit Yanbian University and University of Science and Technology in Yanji, especially HKUST, where there are many small buildings with ethnic characteristics!
I hope you have a good time in Yanji!