Need help connecting hand pump faucet to water tank

Just bought my tiny trailer a few days ago and got my water tank delivered today. I'm wondering how to hook up the tank up to my faucet. My trailer has a built-in sink with a hand pump faucet. Underneath the sink, there is a clear tube hanging from the faucet, but I don't know how to hook this up to the water tank. The water tank has a spigot and an air hole. This is the tank I bought on Amazon:
http://www.amazon.com/gp/product/B001QC ... 01_s03_i00
I posted this question in one of my other threads and someone told me there should be a fitting on the tank. Am I supposed to buy a water tank that already has the fitting or can I buy the fitting separately somewhere? I asked at Home Depot and Fisherman's (outdoors store here in the NW) and they didn't know what I was talking about.
I'm leaving tomorrow for my first trip in this trailer so a quick answer would be much appreciated!
Thanks!
http://www.amazon.com/gp/product/B001QC ... 01_s03_i00
I posted this question in one of my other threads and someone told me there should be a fitting on the tank. Am I supposed to buy a water tank that already has the fitting or can I buy the fitting separately somewhere? I asked at Home Depot and Fisherman's (outdoors store here in the NW) and they didn't know what I was talking about.
I'm leaving tomorrow for my first trip in this trailer so a quick answer would be much appreciated!

Thanks!