I can't edit anything on my wordpress ??

I just got my wordpress installed, but I can’t import my old blog, install themes or pugins, or upload any pictures.
I did however manage to do a “test” post that shows up on my blog. But I can’t touch anything else.

When trying to import the wordpress.com blog, it just says
“Sorry, there has been an error.
The uploaded file could not be moved to /home4/visualo8/public_html/wp-content/uploads/2013/02.” I tried numerous times

When I try downloading a theme it says “Could not create directory. /home4/visualo8/public_html/wp-content/upgrade/pagelines.tmp”

When I try to upload a picture or header: “The uploaded file could not be moved to /home4/visualo8/public_html/wp-content/uploads/2013/02.”

What can I do to fix this? Thank you!