How to prep cotton yarn for tie dyeing

It’s 100% cotton yarn, how do I prep it for tie dyeing, I’ll be dyeing 2 cotton wife beater (it’s a type of tank top if you didn’t know) and they will be going blue, I bought some blue tulip dye, so how do I prep the yarn to dye it?

Did you find out what to do? Since it’s cotton, I doubt it needs any real preparation but I don’t know. Maybe wash it to make sure it’s not got anything from manufacturing left in it. What does the dye label say?

I figured it out, just soaked it for 30 mins beforehand and wind it into a hank, the hank part was tough though .