Steps for transferring wordpress.com blog to .org

Hi guys

Absolute novice here! Brand new to wordpress.org…

Have an existing .com blog and have set up a new hosting account, and installed WP on it etc. Now I’m going through the process of changing the nameservers etc. I just don’t know what I’m doing! Can someone give me a bit of step-by-step guidance?

Once I’ve moved it over to my hosts, I then need to install a premium template which I have already purchased, god knows how I’ll get through that part if i’m struggling with the nameservers!

Would really appreciate your help!

Cheers,
Olivia