No, it is not necessary to blog, but it is certainly a good format for learning to write on a schedule.
There is no "correct order." It's different for every person who decides to write. You can relax and know you'll do it right.
You can use a yellow legal pad and a pen (some very successful internet marketers actually do that) or your favorite digital device. Or you can even just talk into your smart phone and record your thoughts, using voice recognition software to convert them to text.
Just start. That's it. Just do it any way it works for you.
For now, you are not writing for the public. You are writing for you, for your own life and your own growth. Don't even think about other people at all when you are starting.
I still think about a younger "me" and write to her. It's good to write to one specific person in your mind. Sometimes I write to God because I know for sure he's always listening, and I cannot be sure of anybody else.
There are programs to correct spelling and grammar, but there is no computer program to mine the treasures in our hearts and minds.
You are digging for treasure right now, Sherri.
Oh, I forgot to send you this link. It's really a good one. Jane Friedman has been an editor and a writer for a long time. I pay attention to her. http://janefriedman.com/2013/04/01/best-business-advice-for-writers-march-2013/