~snip~
Could I get a wallet I use just for that? Where I can leave the payment QR code in the email and people can scan it if they choose to pay via Bitcoin?
^ It was explained above and I also prefer Electrum wallet which is very easy to use and has a simple user interface.
You can generate QR codes and print in anywhere, you can even capture a picture and send them anywhere that you wanted. But a piece of advice, instead of sending an image of a QR code only, why not send them also your BTC address so that it is easy for them to copy and paste it to their wallet?
There are a lot of process in Youtube regarding this, probably it is also good if you will find your own research.
electrum for me also comes in handy. you need small space in your computer to run this wallet. if the OP wants to know more all about electrum, he can read the threads under this
. he can already see the guide on how to safely download this wallet.