I would take the vehicle to an Autozone, Advance Auto, etc.
Request that they use the scan tool to read any codes that are showing or stored
Write down the code or codes, like code p0305
, which is usually the code for the #5 cylinder misfire.
Go to this website to find out what the codes mean, https://www.obd-codes.com/trouble_codes/
In the video below, after the guy looks at the misfiring coil/spark plug, he uses a tool to check the coil. The quickest way to check if it is the # 5 coil is to switch it with the coil right next to it, if the misfire changes to the cylinder that you just put the #5 coil into , then you may only have to replace the bad coil.
I hope that i have not confused you to much.