Do I just delete the parts that are problematic? I know almost nothing about code and am really worried about making that many changes and screwing up my site.
no – you need to move some of the parts; if you simply delete them, you might break the layout of your site.
if the ads are you main edits, maybe start with a fresh copy of the theme, and after reading a bit about html, re-do the edits, making sure to produce valid code.
Dang. I think I may have to find a different template, because I didn’t edit much. I just decreased the line height for the title and added the script for the adsense ad to header.php, and that is the extent that I did. But there are so many validation errors, it makes the think the issues will remain even if I start fresh.
Thanks for your help.
On closer inspection, is it possible some of the validation error are from plug-ins I installed? The feedburner stuff is straight from a plug-in I found. The the broken link stuff I think is from the broken link detector I use.
some/many of the validation errors are minor and might be from plugins.
you need at least to remove your edits, which ended up in the wrong section of header.php, and redo them in a valid way.
any html code needs to be after the <body> tag.
Thank you so much for helping, btw. I really do appreciate it. I started fresh for header.php, re-inserted the code for the ad, and I now have only five errors.