As long as the store or merchant accept Bitcoin, then you can pay everything in there using Bitcoin. The fee you need to pay and need a time to wait for confirmation is depend on you, whether you comfortable or not. I think it's better if you use fiat or debit/credit card when you're want to pay in physical store and use Bitcoin in online marketplace because it should be cheaper than use mobile banking or digital fiat.
With Bitcoin on-chain transactions, you will need to have confirmations from miners to make your payment valid. Usually merchants will ask your payment (your on chain transactions) to have from one to three confirmations.
Considering the average block time of Bitcoin is 10 minutes. 1 to 3 confirmations will be about 10 minutes to a half of hour or even longer if you make that transaction with very low fee rate. It is more usable if you buy something online and use Bitcoin for payment but it is impractical if you want to do it offline, directly at stores. You will have to wait a little time for confirmations to complete your buying and it is inconvenience.
It is not suggested to use Bitcoin if you need to make a very tiny quick payment since you risk incurring fees that are greater than the cost of the item you are purchasing.
For tiny valued transactions, you will have alternative for Bitcoin on-chain transactions, off-chain transactions with Bitcoin Lightning Network but you will have less choices, less adoption for Lightning Network.