Joanna Stern, one of my favorite technology journalists, has a great article (and video) about the new chip card readers that have finally made it to most stores in the US and how they are a both a step forward and back. See “Chip Card Nightmares? Help Is on the Way.”
But the real lesson is to set up your iPhone (iPhone SE, 6, 6 Plus, and later) with Apple Pay now. Walgreens was an early adopter of Apple Pay, and there are many stores in our area, so I recommend it for your first Apple Pay purchase.
Here are three useful Apple Support pages to get you started:
Using Apple Pay in stores and within apps: watch the demo video https://support.apple.com/en-us/HT201239
Set up Apple Pay on your iPhone, iPad, or Apple Watch
About Apple Pay