Ped, Wow, tough question! Easiest type to learn would be either stick or mig
welding. Mig can be used for welding minibike tubing (typically .083" thick) and
it does a pretty fair job. Stick doesn't work so well because the heat is harder
to control and it is easier to burn through your tubing. Harbor freight sells small
shop migs for a couple hundred bucks or less on sale. By far the best type of
welding for minibikes is TIG. It stands for tungsten inert gas. It produces
beautiful welds and you can damn near weld tin foil with it. The drawbacks
are the cost of the equipment and it takes a long time and lots of practice
to learn. My advice to you would be to see if you can sign up for a welding
class at your vo-tech or highschool shop and take a welding course. That
way you can try Stick, Mig, Tig, and Oxy-acetylene and draw your own
conclusions. Good luck..............Ogygopsis