OK, as long as you're not wanting to weld anything less than about 2.5mm, then go for an arc (stick) welder, You can get a really cheap one form lidl etc (£40) but when you start using thicker rods and more current it will struggle on a standard domestic power supply and keep blowing fuses. You use different thickness rods depending on the thickness of material you are welding, the thicker the rod the more current needed from the power supply. 4-5mm thickness plate is probably going to be your absolute limit with one of these machines with a 2.5mm electrode. My lidl arc welder will not draw enough current to weld with a 3.2mm rod (the next size up) without blowing fuse after fuse.
To overcome this you could look into getting an inverter welder, which are about £250+
Don't use lidl rods (electrodes), they are truly awful. Murex are pretty good.
The best thing you could possibly do is to book in on an evening course at your local college. Its not as easy as pointing a bit of wire and pressing a tigger!
