Emergency please help asap

Up til now iv had a smooth running, great site but today i was messing aroung attempting to locate the file where i could edit my main pages header. I was messing with files like - define_main_page in several different locations since I have a template installed (12541). I can remember also looking at a file named index_default or something similar. To my knowledge i did not change anything as i was just browsing but now my website will not load up on the homepage. Can anyone please help. It will take me months to rebuild everything i have lost, when i know it is something simple

my site is http://www.andys-motorcycles.com/

To my knowledge i did not change anything as i was just browsing but now my website will not load up on the homepage
What were you using to "browse" these files - the application

How were you looking at the content?

ftp application. Core i think. I am trying to get my hands on a backup i made a while ago but it will set me back a bit since its a few weeks old. Preferably i need to find the file/s that i have damaged. I was then opening up the files in notepad so have obviously messed something up but I did not even realise

I was then opening up the files in notepad so have obviously messed something up but I did not even realise
Did you make any changes and upload those files?

What files were they?

Can check with FTP the modified date for files uploaded recently as those are most likely at fault

I opened them up and core automatically updates them if edited. That is the prob, i dont know what or if anything updated, The files i looked at that i can remeber are-

index.php

includes/index.html

/includes/templates/12541/templates/tpl-index-default.php

/includes/languages/english/html_includes/define_main_page.html

/includes/languages/english/html_includes/12541/define_main_page.html

/includes/languages/english/index.php

/includes/templates/template_default/templates/tpl-index-default.php
all the files i looked at were related to the homepage and all as named above, however there are many identical file names found in different folders so the list could go on and since im not any good when it comes to php i am at my wits end

I opened them up and core automatically updates them if edited.
Turn that off

That is the prob, i dont know what or if anything updated,
Did you check with FTP for the modified date for files uploaded recently as those are most likely at fault

marked as edited today. Keep refreshing, i will list them as i go. I dont know what to look for once inside the file

/includes/languages/english/html_includes/12541/define_main_page.php

Thats the only one i can find ??

Replace those files you find from your backup

lol,,,, no backup im afraid. Girlfriend "accidentally" deleted it

Could I not use the file in the origional theme instalation file?

Could I not use the file in the origional theme instalation file?
Yes, if that is the file that seems corrupt now
If not a file that exists in the theme, get a fresh distribution of your same version from
http://sourceforge.net/projects/zencart/files/

Well to be honest I have been hoping to change the theme for a while now but never had the nerve to do it with this being a business website. If I try to upload a new theme and install it is there a chance that it might figure itself out? Im gonna give it a try anyway and if not il have to start again. It wont be too bas as I have backing up my files as we speak so I can use all my old files and images. I dont know what else to try apart from that. I already tried updating the file i mentioned just with the origional theme file but no good, i dont think that is the file causing the problems

If I try to upload a new theme and install it is there a chance that it might figure itself out?
Only if it is a theme file causing the issue

Try switching to the classic template and see if it i a file from the other theme

Also,
https://www.zen-cart.com/tutorials/index.php?article=82