My dear friend.
There is this amazing thing that came out many many years ago. It's called "Google"
You can find all the answers you seek there. Just be sure to understand you need listen and learn from the right people. There is so much wrong SEO advises, myths and bogus tactics it's easy to get caught up in it all.
Today SEO is more about making money from clients then actually ranking websites. So. just be careful on your long journey and taste for knowledge. SEO is simple really, just a few simple concepts you should always keep in mind.
Network with the right people, watch and learn how others do it and see the results. Do I recommend on taking a course? Well, it really depends on the type of person you are. (for a number of different reasons) ie. Are you a good self educator?
Hope that helps.