Go to the local junk store or even spend some $$ on some 1/4 or 3/8 steel.
And start playing. Welding is a fun pastime that pays off.
IIRC you have a press, and that's how you can tell if your welds have penetration and aren't cold or hot... Our benchmark in school was starting at 15 tons, and you had to double that or better to pass. And when you know how, that's easier than typing here....
Another hint - if it sounds like frying eggs, you got the arc right.
But yeah, the key now is to practice, practice, practice. Run beads, start doing fillets, doing 90's, damn. This is a skill you'll use for the rest of your days. At least now they have auto-dark helmets (I learned with a 2x8 screen - and a solid flip down helmet - them bad ol days)... make sure you have good gloves (more when you pick up that 1100 degree hunk of steel and forget it's 1100 degrees) and keep you from getting flashburn... and at least a thick cotton leather long sleeve shirt if not welding leathers. (Yes, they're kinda worth it).
Your gloves and leathers (or shirt) are all expendable (not immediately, but I've replaced gloves some once a year, leather welders jackets about 3-4 times) but the real key is practice, practice, practice. Take a class at the local community college, watch youtubes about beginning welding, learn what a good weld VS bad weld is...
And go to town. Because it's like magic - taking something no mortal man can bend, and joining pieces of them together like you are Thor and his hammer, and learning how to make it stand up to 35 tons or more of stress - so you can build awesome goodies.
