Welding for the first time - need advice

Thanks for the huge response everyone. The weather is going to be iffy here for a few days so I'll probably give it another shot at the end of the week.

I did notice the gas gauge moved when I'd pull the trigger but I didn't hear or sense anything was coming out. I'll have to give it a listen or use the lighter trick next time I'm out there. I'll take your flow rate suggestions and make sure I have it set to that next time I try it.

I double checked and I have solid core wire on there and the polarity is correct.

I bought a piece of copper today to use behind the metal but it is possible to weld this without a backer right? When I do my quarter panel patch, I don't know if I'll be able to get the backer in there with the trunk extension in the way.

The flange tool is another good idea. I've read different opinions on whether or not it leads to more rust later on but I guess I could just always use weld through primer on the back to help prevent that.

I also watched a bunch of youtube videos all week but they didn't seem to help too much. The guys just kind of quickly explain what to do, pull the trigger for a second and a perfect weld comes out of it. Didn't work nearly as well for me in real life :D