"How to Top Marijuana"
"How to Supercrop"
"How to do LST"
Type each into google, and read corresponding results. Growweedeasy.com is a good source for a lot of beginner info that I highly suggest you read through if you want to be truly successful.
You can find a LOT of info right here on RIU as well, but you have to do a big of digging around at times to find it.
Normally Id try to actually answer your question myself, but with how broad/encompassing marijuana "training" can be, it's best that you do some reading on your own, using the search tags I posted above... get lost down a rabbit hole of reading, and I garuntee you come out on the other side a much more knowledgeable (and hopefully skillful) grower