moving wordpress to another hosting company

I am not a techie. I was going to change hosting companies and thought I could just move all my files by backing up my whole site but found out that it is more complex than that for wordpress sites? Someone told me that there is a wp-config.php that is not just in your “files” but out there somewhere and when my old hosting company closes my account if this file did not get “moved” along with the other files my site would not work at my new hosting site. Are there instructions anywhere on how to move a wordpress site from one hosting company to another. Or do I have all this wrong? Goddady does not offer this service or others will “migrate” it over for around $100.