There are a lot of ways you can shop and pay using Bitcoin, and this reply will not be enough to mention all of them, so it is better to search on Google to get more results.
The easiest ways are:
Use this site[1]: you can shop in many stores"not that accept Bitcoin only" and then copy the product link and paste on that site.
Buy Amazon gift cards using [2].

[1] https://www.thebigcoin.io/
[2] https://copay.io/