Noob question. Domain registration and hosting.

Having never done this before, I'm a little sure where to start.
I know the domain I want (its a .net) and know that it is available.
Now the next step seems to be take the step and get it.
This is where I am stuck....

I've heard that hostgator is best for hosting, and plan on using them.
It seems like their domains are more expensive than godaddy though.
How do I go about setting it all up? Do I get them both at the same place?

You can actually get the domain and the hosting at 2 different places.
You'll have a control over the DNS settings of the domain which is the instruction to make it point at a server.
Whenever, you'll register to a web hosting company, you'll receive an email with the nameservers which you would need to set at your domain level.
Within a few minutes (up to 24 hours for full propagation), your domain will work with your hosting.

I dont recommend getting your domain with your hosting company.

Get them on different company.

Use godaddy or namecheap for domain, and for hosting check legit reviews.

If you get it with your hosting company you will be stuck forever with them.