Can I use my sim card?

I have boost mobile as my phone carrier. I ordered a pre owned iPhone 7 plus off the boost mobile website. Can I use my sim card that's in my LG
stylo 4 and put it in my iPhone to activate the phone? Or would I have to buy a new sim card?

It should come with a new SIM already installed. If you are to use your old one, follow the instructions exactly.