First of all, you’re not alone if you’ve never canvassed before. You will be partnered up with someone more experienced and you’ll have a script you can refer to. Once you get the hang of it, it’s actually weirdly fun, even for introverts. Check out opportunities here.
But for those who want more preparation to get started, here’s some resources.
New article from Indivisible on canvassing here.
Take the quiz here.
Resistanceschool.org offers a lot of other interesting courses on political action and it’s free. Sign up here.