Welcome to the forum.
A lot will depend on what you mean by "crop," and on what you want to end up with. To do what I think that you want, you would use the fixed Effect>Motion>Scale, to increase the total size of the footage. This will "zoom in" on the subject. All of the extraneous material in the scene will not be seen. The Frame Size stays the same. Now, any Scaling will degrade the image to a degree. How detrimental this is, only you can determine.
There is also a Crop Effect, but this just cuts out the background, does not increase the size of the subject, and places black borders around the subject.
Let us know exactly what you wish to end up with, and someone can direct you.
Note, however, that you may have some challenges with this particular format. It looks like it's possibly a non-standard video format -- and that can mean you'll likely be struggling with it in Premiere Elements.
Is this from a still camera?
What type of camcorder did it come from and how did you get it into your computer?
Hi! I used VisiCrop earlier. I think it's a very simple program.
Yep, it is. visifly.com.