Stick welding is harder to master, and very easy to blow holes - while I can use a stick welder on thin steel, the mig is much easier and cleaner.
Mig is much easier to learn, BUT:-
Get a full size gas bottle - the tiny ones are too small.
Don't get the smallest welder - I have two. A 250 amp one that is brill, and a smaller 150 amp " small professional" one. Don't ask me what make, I can't remember, I've had them for 15 plus years!
You do get what you pay for - and a small professional one will knock spots off a cheapo machine mart one anyday.
Get one that takes big reels of wire.
And practice loads, with different thicknesses of steel till you have it right.
While professionals might be able to just get stuck in, I don't weld so often, so I always do a trial piece, to make sure that the kit is working properly, I have the right amps and I've got my eye in.
Practice loads, starting on thick mild steel offcuts and then progress to thinner steel.
Have fun.