if you learn to stick weld, you can weld with pretty much any process. even if its an AC, it still worth firing up and learning on, no reason to go shell out a bunch of money if you have something that will work to learn on. i learned to weld with a lincoln AC buzzbox... that my dad gave me. they definetly have their limits, but you can still make it work. go pick up some 6011 and 6013 sticks and start laying flat beads, lots of guys will say to learn with 7018 but i find it is easier to see the arc and puddle of a 60s rod, which makes it a whole lot easier.
once you can put down a nice flat weld, try joing some pieces! dont forget to post some pictures!
98 XJ- 4.0L, NP231, AW4, chryco 8.25, 4.5" mid arm 3-link, 285/75 Herc terra tracs on moabs, V8 ZJ tie rod, fabbed bumpers...