Hi and welcome to the wonderful wacky world of knitting and to Knitting Help! Holding the yarn in your left hand is Continental. Which should you do? Whichever works for you. I knit Continental and am trying to get the hang of English style but it's hard, really hard, for me. Being able to do both is a plus. I learned from a book I got in kit (it had a book, needles, a few other things) from WalMart, then didn't make anything because I couldn't figure out anything beyond knit and purl...until I found this forum. Now I'm convinced I can knit just about anything, someday. Joining a group or class of some kind could be a good idea. I often think it would really nice to have another knitter nearby. You will learn to recognize mistakes and there is always this forum for getting help. You've already discovered the videos. The glossary is really useful too and some of the entries are linked to videos. Enjoy!
I should never overestimate my basic arithmetic skills.