1) If you want to walk along the beach and explore small fishing villages, you should stop in Hawaii. They have much prettier beaches. Galveston is a tourist town. You can certainly walk along the streets and even hop on a free trolley to see some old buildings and other areas. But you may feel quite lonely after a couple of days going all by yourself . It will get rather hot as well. It is hard to talk to people if you do not have some decent knowledge of the language and the customs. My advice: carry a small writing pad and pencil so the people can write down the names of places for you, or to draw a map to help you find your way.
2) Try to get two credit cards (Visa and MasterCard--other cards do not work well because you are a foreign visitor) and keep them in separate places. Make sure you know how to use them. Most people here are honest, but you should still need to know how to check in case there is a mistake. Get some Traveller's Checks if you like, but keep them for emergency only. Also, exchange some US dollars in town (not at the airport) before you leave so you can buy something when you arrive. A cell phone may also be handy, but not really necessary.
3) The Galveston hostel is inside a beach motel. You share a room with several people and you sleep in a bunk bed. Have you been in a hostel before? It is like living in a school dormitory. There is not much privacy. But you can sit around and talk to other travelers in the living room, and use the small kitchen to cook food if you like; or go out and buy food to eat. Bring sun protection: a hat, sun screen lotion, and insect repellant also.
4) I know you don't want to stay with Chinese people because you are coming here to learn to speak English. People will tell you that you can learn faster if you are forced to speak English only. That is true. But I thought you might find the new American customs a little too much at first, and so it would be good to have someone around who could speak Chinese if you need help.
5/24 I am just curious: of all the thousands of colleges and universities in America to choose from, why did you pick the University of Central Oklahoma? Will you be taking a short English course only, or will you stay longer? The University is in a small town, so you will be able to see one close up, without going to Galveston. Have you traveled in foreign countries before?
I am afraid you may have problems going by yourself if you do not drive a car. One piece of advice: make sure you carry a credit card. Either Visa or MasterCard will do. Most people do not accept personal checks from an overseas bank, and carrying cash is not a good idea. Many places do not take Traveler's Checks either. Many, many years ago I came to America as a foreign student from Hong Kong. I went through the same kinds of difficulties with the language and the lack of knowledge. I am writing to you in order to be able to help, as I understand how you must feel. Please do not think that I am asking too many strange questions. The more information you can give, the more I can help you.
It is probably too late now, but I would suggest picking a school in Houston, or San Francisco, where there is a large population of people from China who do speak Mandarin Chinese. In Oklahoma, it is unlikely to find too many. Hotels are generally quite expensive, especially for only one person. If you stay longer, you may be able to rent a tiny apartment by the week or by the month.
The U. of Central Oklahoma should provide you with a dormitory since most of their students will not be staying there during the summer. The regular school year ends late May or early June. Buses are not very convenient, and taxis are very expensive. It is cheaper to rent a car; but that is not an option if you do not drive. It would be better if you could find a friend to travel with you and to share the cost. It takes a long time to learn the English language.
The best way is to stay after you have finished the English classes and then travel and practice using the language everywhere you go. You will understand and enjoy what you see a lot more.