Hi, Shajmc, first, welcome to the forum here.
Browsers load stylesheets in the order they are called in your html, so you should have your sites working stylesheet (usually style.css) called last - after all other stylesheet calls.
Browsers will follow the last instructions given for a class or id.
So what you want to do is add any classes you want to alter, to your style.css file and never edit the ect css files.
This will make it "updater proof" meaning when you install new updates, you typically will never need to make those edits again..
If you do not follow this, you will make your update installations more time consuming.
It sounds like you are using paypal express and that will place a button first checkout page because it will collect the address from paypal and bypass that page in your cart.
If you do not want that service, you can turn it off, or choose a more suitable paypal service.
I'm not sure if you can change those buttons, I believe the buttons are generated by the connection to paypal.
For the icons, I would need to understand which icons you are referring to...
For the home link, I believe you would find that in categories and set the url to any page you like.
It typically has the "working name" of Category Root.
The digital download feature is covered on this page -
https://www.ecommercetemplates.com/help/digital-download.aspThe parameters you list would be in the vsadmin>includes.php file.
If they do not exist, just like any of the parameters (covered below), you simply add them in.
There are a world of parameters you can set to control many aspects of the cart.
On the "How it works" menus on the left of this page, there is PHP Parameters
https://www.ecommercetemplates.com/phphelp/ecommplus/parameters.aspI think I covered it all - please post back with any more issues.
The forum search (top right of this page) is a valuable tool to search where others have had the same questions as you.
Thanks (or rather Cheers Mate
),
David