Do I have to pay for calling from the hotel room?

It depends on the rules of your hotel. You'd better ask your friends who have stayed in this hotel first. They must know. Or ask the hotel waiter.

Generally speaking, if the conditions are better, calls are usually made free of charge (this is generally a higher room rate, which is also included in the room rate), but local calls and long-distance calls are also charged (generally, you need to pay extra when you check out). Calling from inside the hotel is absolutely free.