Correctionsn in red. Stylistics and variants in blue.
A Wonderful Trip to/in/through the American West
We finally returned/came back to Tampa today after 21 days of travel in/through the western states of America. We've saw the magnificent Grand Canyon, beautiful Grand Teton, and the amazing Yellowstone. Yosemite too, of course. I was awed and amazed by nature, which was created by God, our only and true God. Thanks for creating everything, ourselves included.
Some of the places you mentioned are not on or near the "coast". That's why I think it's better to refer to "the American West" or the "western states".
"Shocked" is somewhat negative, so I substituted "awed," which is positive.
I enjoyed reading your post, and am so glad that you were able to see some of America's treasures.