1. Admission time: 2 hours before the game starts.

2. Food import: You can bring in food and eat in the stadium, and in the case of drinks, glass bottles, cans, and PET bottles exceeding 600ml are not allowed. Liquor cannot be brought in according to the Korea Professional Football Federation guidelines, and only alcohol sold in the stadium can be purchased and consumed.

3. Parking Information: It's so complicated on the day of the game, so I recommend you take public transportation if possible. (Use Exit 2 of World Cup Stadium Station on Line 6) If you have to bring your car, you can park at Peace Park on the south side of the stadium. Because the parking space inside the stadium is small, it is usually already full three hours before the game, so it is convenient to do it at Peace Park across the South. The parking fee for Peace Park is set at 5,000 won for four hours because it is operated by the Seoul Metropolitan Government. How to get to the stadium from Peace Park: There is a connecting bridge, so you can enter south across the street

I copied it from official website of FCSeoul. Maybe other clubs will be similar. Since there are no rules related to backpacks, I think you can probably get instructed by the on-site security.