Can anyone help??

Here's a question for all you techies out there. I found a new template that I want to use on this blog. I've downloaded to my computer & then tried to upload it to my HTML template. It gave me some error message.

I then switched to classic blogger mode & inserted the new template that way, which worked fine, the only trouble is that in the classic version, the customize page elements feature is not available, which I really need. I tried upgrading back to Beta blog, but I had to chose a new template, & it won't let me use the new one I've got.

Does anyone know how to use a new template in Beta blogger?? I'll be your best friend forever. You can either leave any suggestions in the comments section of this post, or send me an email. Thanks.