If you mean /skin1/customer/home.tpl - the answer is yes. BUT -- that's not always the best place to put your code... you should look at home.tpl as an outline or shell for other template files.
"Main page" -- do you mean welcome.tpl ?
The answer is -- get to know WEBMASTER MODE and learn the template structure. Use a text editor linked to an ftp client.
Go slow, work around the smarty - in fact, USE smarty to your advantage, and you will be able to do just about anything.
Thread moved to
Storefront Design & Template Editing