There are lots of issues that get pretty involved, so without any detailed explanations let me just mention a few of the vital concepts you need to be aware of:
I can pay monthly and own all the content on the Wix site.
You do not control, and so in some ways do not really "own," anything on a free site. Read just a little and you will find many cases of people who have had their sites closed down, losing everything, because the unknowingly violated some apparent rule of the person operating the free site.
You need to have your own domain registered and choose an independent host. Then you will own the name, and everything on it. You can put it up, take it down or do anything you want and move to another host anytime you wish. It is yours.
There are many limitations on free sites. Normally, at least without exorbitant expense, you do not have your own domain and links to your site will be lost if you do get dropped or move. Mostly you cannot put ads on your site or control other money making opportunities.
Buy your own domain. Get hosting on a good host. Have them install WordPress for you. Learn a few basics about WordPress and you are off to the races. Lisa has lots of honestly great information to teach you all you need to know and you can ask your questions here.
You can still use your dreamweaver to help you prepare html, etc., you want to insert on your site.