The phrase "couple things" means a few things or a small number of things. It refers to a small amount or a limited number of things that the speaker wants to mention or discuss. Full definition
Alright, if you are planning to order this game, you need to know couple things about it. (amazon.com)
And how we lead our companies, makes all the difference in the world in whether you're on the front line or you're the CEO, we all want just couple thing in our careers. (lawyerist.com)