how i can make contact for free to showe our hotel to showe everyone to know that '

Do you mean "how to show that your hotel is available for tourists to use?"

If so, create a website and give your prices and directions to your hotel. A map is helpful. Some photos of the rooms is helpful. Setting up the website is not free but once it is running you get your name out in public. Then other customers can make endorsements or reviews and the rest is history. You have to pay a little to get a little back.

Pull up some other hotel websites and see what make those websites work. Even some cheaper hotels that have rooms in the 500-600 baht range have websites.

Up to you.

Promote your business through TripAdvisor.
It is the most popular site worldwide and you will surely have many people reading about it. Another tip is ...after you register and have the hotel on TripAdvisor, do urge your guests to write about their visit so other people read about the services the hotel provides and become popular.
This is a good alternative. Good luck.