Depends if you are looking to become a vendor or affiliate, even so whatever you choose there is no magic bullet, you need to read, read and read some more, then implement what you have learned.
Learning HTML would be a good start as you can then build you own sites which are needed for both an affiliate and vendor.
IMO don't waste your time with SEO, it's the most unproductive thing you can do with no guarantee of success and you are always at the mercy of google.
Find a way to generate traffic and then SCALE IT UP!