Hey franziii,
ich habe dir mal ein paar Fehler verbessert. Wichtig ist, dass du ein Summary immer im Präsens schreibst und denk dran "he/she/it...."s" muss mit" 
On the Gibsons vacation they travel to Kings Canyon National Park. The children, Debbie an Rick, heared a story about a bear who attacked a tourist of the ranger Ed the week before. The next day their parents want to see the General Grant Tree but the kids think that it is a boring idea. The Result is that they stay at the campground and played cards in their motorhome. But Debbie wants to see the bear and Rick thinks that it is too dangerous. They take food with them and go hiking. Suddenly Debbie shouts that there is the bear but it is only a joke. Rick is hungry and so they stop for having a picnic. One time Debbie looks into the forest and suddenly she shouts that there is the bear. But this time it isn't a joke. Now Rick sees the bear, too. Then the bear runs to them and the children goes a few steps back. Debbie falls down but she finds a stone and throws it on the bear's nose. So the bear stops and goes back into the forest. Debbie and Rick run back to the campground. The shock is big.