Does anyone here have any experience with Avaya?

I just started a new at-home job training to do on-the-phone customer service work. I purchased the requisite landline telephone with a headset plug for training. Now it’s starting to look like I need a USB adapter for my headset. Is this correct? I can connect to Avaya, that’s not an issue. I’m just concerned that when I actually begin using calls, I’m going to be using the wrong headset/port. I know, I’ve already tried to ask the instructor – didn’t really get a straight answer other than, “yes, you’ll be using Avaya to take calls”.