Photo album problems

Hello all. I'm fairly new to all this CMS, php, MySQL stuff so go easy on me.

I've set up a web site using PHP Fusion and I absolutely love this system. Only problem is I've having trouble with the photo albums.

On the page to upload a photo I get these lines at the very top:
Notice: Undefined variable: modlevel in C:\Web Server\htdocs\administration\photos.php on line 27
Notice: Undefined index: in C:\Web Server\htdocs\administration\photos.php on line 27

And when I actually post a photo all I get is this:
Notice: Undefined variable: photo_id in C:\Web Server\htdocs\administration\photos.php on line 61
Fatal error: Call to undefined function: imagecreatefromjpeg() in C:\Web Server\htdocs\maincore.php on line 615

Am I doing something wrong? Is this easy to fix?

Any help would be greatly appreciated.