Trying to weld, I’m terrible!
For sheet metal I use 0.023 with CO2/argon. I'm not a big fan of butt welding on old metal. I use the stitch method keeping the tip close and near vertical. Its a short burst which is less than 2 seconds unless you are plug welding using punched holes. You just go back and forth until all the welds join making it a complete weld. I usually use #6 Tek screws to hold the metal together.