I weld structural steel for a living, out in the field. Stick is a great process and you can do a lot once get a handle on it. I agree with everything manny66 posted. You'll wanna keep your 7018 rods dry at the very least. I learned by burning piles of rods. Start by running beads across a 6" wide piece of plate, and keep stacking them... basically "padding" the entire plate. You'll wanna focus on keeping the beads in a straight line. After doing a bunch of that you can build up fillets on thicker angle or by welding three pieces of flatbar together in a X shape and filling in each corner. I would focus on just learning with 7018 though, and use your wire wheel/grinder to clean the metal first; people often say you don't need to clean with stick but it always works better on clean metal.

You can also do stainless with stick but it's a bit trickier and if you really hate yourself try stick welding aluminum sometime