At the heart of it, all welding is the same.
Apply heat to melt the item(s) you are welding and melt the joint zone without melting it to the floor, possibly add some filler, and achieve a Zen state of oneness.
It's the fine process details that change from process to process.
Automotive-centric welding?
IMHO, probably MIG (technically GMAW

) for most general-purpose stuff. Fussy things (tubing, aluminum stuff, roll cages, etc) might be TIG (technically GTAW). Rarely stick (technically SMAW), unless for 'thicker' brackets or such. Rarely oxy-acetylene welding, although using the oxy-acetylene torch to heat things (aka 'the blue wrench') or to maybe braze something might happen.
YMMV and all that.
If you can find something, some community colleges or adult education schools offer various 'Intro to welding' classes. Look for one geared (Ha!) for hobbyists, and not a 'welder certification class'.
All welding comes down to "puddle control". How big, how deep, how fast to move, how much filler to add, etc, are variations of puddle control.
Oxy-acetylene can teach (or show you how much you need to learn and practice some more

) about puddle control. Without dunking the tungsten like in TIG.
With GMAW (aka MIG), you still need to watch and pay attention to the weld puddle.
The general 'problem' with MIG (more specifically with short-arc transfer mode GMAW) is that one can make what 'looks' like an OK weld (because the weld bead generally 'looks' OK, at least superficially or to the untrained eye) but the weld never melted into or fused into/with the piece(s) being welded. Called "lack of fusion" or "lack of penetration" or "cold lap".
Practice, practice, practice.
Want to start practicing with that MM211?
Get some 1/8" thick plain mild steel. Use C25 shielding gas and either 0.023 or 0.030 solid filler wire (I like to stick with a name brand wire, like Lincoln L-56, so that you are not 'fighting' some unknown set of variables with wire 'quality'), RTFM or the parameter door chart for what machine settings to start with, lay one piece of the steel on top of the other to achieve a "lap joint". Start the weld, watch the weld puddle (the molten steel, not the bright arc!) melt into BOTH pieces of steel and the filler wire flow into and build up the puddle to the appropriate bead size without melting away the top edge of the top piece of steel or melting right through the bottom piece of steel (the lap joint configuration helps here by giving you a visible edge to follow and also having two thicknesses of metal where you are welding). Keep practicing.
Welding on the floor *****. Get (make or buy) some sort of 'welding bench/table'. Even the H-F folding one (on sale it runs about $60-$70) and it is actually worth it IMHO.