Unfotunately i live in Kent so won't be able to come down and help but when i left school i started at a local garage and my boss offered to teach me a bit of mig welding. He gave me a bit of sheet metal and just told me to learn to write my name in weld, this gives you hand control and trains your eye look at what you're welding. Start with a low setting first so the weld sits proud on the metal then turn up the power up in stages to get the weld flatter, ie more penetration.
Use 0.6mm wire as 0.8 is too thick for thin steel and get a gas set up not that gasless wire,although some people can do quite nice welds with it i've never been able to.
Where ever possible support your torch with your spare hand to stop you wobbling about and try to push the weld rather than pull (although pushing is not always possible)
As with most jobs preperation is the key, so spend that little bit extra time cleaning the job before you start.
This is just how i started welding and is just the basics,other people will have other tips and it's just a case of pratice makes perfect and finding what works for you.