Radio Slave Flash Trigger Help

Hi, I am new to studio photography and have a question that may seem silly to some. I have been trying to research online, but with no luck.
I have a Canon EOS 20D, 2 softbox lights and an umbrella.
In order for my slave flash trigger to fire all three lights, what do I need to do. With what was supplied in the kit, I have one hotshoe and one receiver.
Please help..Thank you so much.

What type of lights do you have, as well as what type of trigger are you using?