I bought one of the Ark welders from Lidl a few years back.
Watched a few youtude vids, and promptly set my hair on fire.
I found some old rusty tools that were never going to be used again and started joining them all together. Great fun until you find you wanted one of the metal files in the middle of your sculpture.
I did a fair bit of welding with it on the frame of my CX500 project. I got OK on it when I figured out what setting the machine needed to be on for different welding rods.
The machine I bought was only a small hobby one, with a short working cycle, meaning it would overheat quite quickly and took an age to cool down, to be able to use it again. I started using a desk fan to help cool it while in use which helped. Better machines have fans, longer working cycles and more power to do more things. I think mine is around 80amp, but does for the messing around and basic stuff I wanted it for. I did blow a few holes in the frame of the CX500... not great, but I did repair them.