Are it illegal to "reject your own drinks in our store" and "forbid eating non-our-store food in our store"?

It is an overbearing clause, but it lacks basis in applicable law and generally the lawsuit will not win. If you have a dispute with the store, you can complain to the Consumers Association and they will mediate. You can also file a lawsuit in court, but I don't think it's necessary. It's a trivial lawsuit.

I think this issue should be handled this way. Negotiate with the store in advance and bring your own drinks or food. It is best if both parties reach an agreement. If not, you can find another hotel.

The store’s slogan is illegal, but reasonable. After all, restaurants make money from food and drinks.