Payables vs Pay expenses shortcut

Hi there, I'm very much new to bookkeeping. My partner and I have recently started up a business and our bookkeeping friend insisted Sage 50 pro accounting is a must learn and use for me to take care of all our bookkeeping needs. I know she is a very busy lady and I hate to pester her all the time with questions so I thought id ask here.

Payables vs pay expenses for inputting receipts -Canadian tire supplies receipts, Home hardware supplies receipts etc etc...these receipts do not have invoice numbers on them.
We have one supplier we go to regularly that provides a receipt with an invoice number. Would I put all these suppliers under pay expenses or would I be inputting these separately?

Thanks so much in advance!