I suggest not joining the tour group, but joining a one-day tour group. I suggest going to Old Town of Lijiang first. It's beautiful. There are many interesting projects, such as horse riding, boating, high-altitude wetland park, and re-walking the ancient tea-horse road in Lashihai. You can also start from Lijiang to Yulong Snow Mountain, Lugu Lake and so on.
After May Day, it is considered as the off-season, which costs less and can also experience the corresponding beautiful scenery. Note that the incident is not with the group. Secondly, if you don't join the group, you don't have to pay the maintenance fee of the ancient city. Secondly, it is recommended to stay in an inn and book an inn online. Someone will pick you up when you get there.
You can eat more peaches in Old Town of Lijiang. They are nourished by the snow in Yulong Snow Mountain. They are very sweet and delicious. Snacks can be eaten in one street, which is cheap and delicious. It is recommended to shop around for shawls. There is a big temperature difference between morning and evening, so remember to bring your coat. Sun protection at high altitude is very important. Remember to prepare sunscreen. Drink plenty of water to avoid dry weather, colds and sore throats.
Shangri-La is very beautiful. It's cold and wet in the morning. Remember to bring a thick coat, or rent clothes in 50 yuan at least once. Remember not to be fooled, yak meat is really not worth 240. Altitude sickness. I think normal people are fine. Just remember to avoid sleeping when the altitude difference is big. I am in general health, not very well, but I have no altitude sickness.
Personally, I think Old Town of Lijiang is the most beautiful and worth visiting. Bar street is expensive, but it is open-air and you can see outside.
The road to Lugu Lake is really difficult. Although the lake is clear, it is not so simple because the people there are commercialized. If you attend a bonfire party or a dinner party, it's really not cheap to go to 200 yuan per person, but it's worth it if you want to see it. The bonfire party is so small that you can't find the imaginary scene. In Lugu Lake, it is worth buying silver, which is much cheaper than other places!
Fang Gang, the national blood of Shangri-La, remember to avoid conflicts as much as possible. The strength of national unity is amazing. It is recommended to take the train, which is cost-effective and comfortable. The most important stop in Shangri-La is Pudacuo National Park. Remember not to participate in stamping when you go in. A stamp of 10 yuan is useless. Secondly, if the temperature is ok, don't rent down jackets or buy oxygen, which is a complete waste of money.
I wrote an article about a half-month tour in Yunnan, and I can send it to you if necessary.
The above answers come from my personal experience and I hope to adopt them.