MIG welders are wire feed. Wires are commonly available for steel, stainless, hard-surfacing. You can also get aluminum MIG wire, but you generally need a spool gun to pull feed the wire, rather than push feed it. Aluminum wire is notorious for sticking in the welding gun. You need an inert gas for aluminum MIG.
There are small models you can buy for 110v operation. You can also use a flux-core wire (for steel) in them, so that you can scrape by without bottled gas.
MIGs are easiest to learn to lay a bead with, and are very nice for doing light sheet metal with, because the deposition rate is higher and lessens the chance of burn-through.
With the advent of new auto-darkening welding helmets, learning stick welding is not as bad as it used to be, either, since you can see a bit of what is going on while trying to strike an arc. Stick welders are considered more versatile, because of the variety of different rods you can use, for different metals, weld strengths, etc.
PS: don't burn your shop down. You need a workplace free of combustibles from flying sparks and gobs of hot metal.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)