WordPress comes in two flavours: WordPress.com managed hosting, and WordPress.org self-hosted.

Which WordPress plan to choose?

The WordPress.com pricing page details the WordPress.com hosting plan prices.

As of 28th November, they are:

PlanFreePersonalPremiumBusinesseCommerce
Cost$0$5$10$33$59
Custom Domain?NoYesYesYesYes

WordPress.org needs to be hosted on custom web hosting.

A domain name typically costs $14.99 / year, and web hosting normally costs from around $8 / month.

Americans can use a web host like Blue Host.

Australians can use a web host like Insight Hosting.

How to find the best WordPress web hosting