You can go to a website, such as www.the-qrcode-generator.com, to create one for your church. You put in the website that you want (for instance, if you want to put a link to a page on your church's website about your church's Resurrection Sunday service, you can put that link if you create one - e.g. www.yourchurchnamehere.org/resurrectionsundayservice), or even a link to your church's social media page, and then you can download the QR code onto your computer as an image. If you choose it to be a static QR code, you can only use that QR code for that one website, but if you make it a dynamic QR code, you can change the website every now and then and just use the same QR code for other opportunities as well (however, you will have to then register for the website to be able to change it in the future).
When you save the QR code onto your computer, it may make it a zip file; if so, then you'll need to first extract (or unzip) the file before you can use it. You'll either want a .png or .jpeg/.jpg file if possible. You can test out the QR code above. It leads to the website of my upcoming book, Using Technology for Your Church: A Guide for Pastors and Church Leaders. Be creative in how you use the QR code for your church, and be sure to list above or below the QR code that it is a QR code and that they need to scan it into an app (especially if your church is small). An example sentence is: Scan the above (or below) QR code into your smartphone's QR Scanner app to find more info about _______.
This is a bonus lesson on technology for your church which is not found in my upcoming book Using Technology for Your Church: A Guide for Pastors and Church Leaders. Be sure to get the book when it comes out soon. Check out www.helpingchurchesgrow.org/churchtechbook for more information. If you purchase the book, you will also get a link to get bonus materials. Also, check out this new endorsement for the book: