Setting up a Point of sale Sheet

Good afternoon, 

I was thinking of setting up a POS/point of sale sheet on excel. I googled it and found instructions on how to do it. But the person that was nice enough to post the information wrote it assuming that everyone knows how to enter Macros etc..

Then it came to mind that I should check here. 

I did speak with tech support and they directed me to a template names "Inventory Management."

It is very close to the idea what I could use. But I think I need to add a few things. My only question is how. 

What I would like it to have is a sales colunm.  If you do a google search on How to set up pos in excel yu'll see instruction on wikihow.com 

What I'd like it to do, is minus the item, and fill the profit colum and update the inventory colum etc..

I also would like to see if I could create a barcode from Item Number and scan a lable on the item.

But I'm not the only one that says its to vage, 

So, If anyone has any ideas?

or has set up a POS with smartsheet. I'd really appriciate your input. 

Thank in advance,

Jay