The Jiuzhaigou Valley Area can only be accessed through the main entrance gate. You will have no difficulties finding this gate, it is by the main road, just follow the crowds. But the best way to get from your hotel to the Park, is by taxi. They are really inexpensive.
Once in the ticket office, you have to buy two tickets: the park and the bus passes. Even if you want to hike, I recommend buying the bus ticket. The Park is too big to visit everything on foot. If you did not get a tourist map from your hotel, you should buy one before entering the park.
In the picture you have the Swan Lake, where swans can be seen.