1st time welder

so I went out today and bought a chicago electric welder from "harbor Freight" for $250. I really wanted a quality american made welder but for a first timer i just couldnt justify the extra money. On the plus side I got a 2 year warranty for $34! What is everyones experiences with Chicago electric?

Tomorrow I will go to the local welding supply and look at gas (im thinking an argon mix based on everyones responses). I am also going to pick up sheet metal so i can begin practicing. What gauge should I be using for my mini tub project?

I included a few pictures of the welder and my girlfriend wanted to model so we had some fun with it lol. Thanks for everyones input its greatly appreciated and I cant wait to get started welding!

-Gabe