site moved servers and updated, now having error messages

My site was moved to siteground, and zen cart updated to v.1.3.7
Now I am having some trouble and the gal that helped me isn't responding.
Perhas you guys can help a knucklehead like me figure out what is wrong. Warning, guidance needed in knucklehead terms, Thanks
ok, so first in actions, the image button isn't there anymore
When I go to Products image manger, it shows this error

Warning: Cannot modify header information - headers already sent by (output started at /home/themonke/public_html/admin/includes/languages/english/products_image_manager.php:188) in /home/themonke/public_html/admin/includes/init_includes/init_templates.php on line 36

I also cannot modify any info pages
It shows this error

Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /home/themonke/public_html/admin/infopages.php on line 466

Warning: reset() [function.reset]: Passed variable is not an array or object in /home/themonke/public_html/admin/includes/classes/object_info.php on line 29

Warning: Variable passed to each() is not an array or object in /home/themonke/public_html/admin/includes/classes/object_info.php on line 30

Any ideas on where to start fixing this mess? It's really ticking me off.
Thank you so much!

Start by re-uploading this file admin/includes/languages/english/products_image_manager.php and see if this corrects or spawns another error message

(kuncklehead here) Where do I upload from? Should I copy the file? Should I delete the old file?
I can find the file in the control panel, files, but I need hand holding. However, I learn quick.
Thank you

In the top bar here on this site - select home and then download the zip of Zen Cart - unpack this on your local and you can follow the tree structure to the file you require and upload it to your host