To use the WordPress framework, you need to have hosting and a domain purchased with a hosting company.
In the course, we recommend and show you step-by-step instructions on using Dreamhost (one of our favorite hosting companies) but you can use whichever hosting company you wish.
This cost is around $100 – $200/year depending on what company you ultimately choose and is an annual fee paid directly to the hosting company.
Other than that, everything we teach in the course, we use the free version of plugins for, but I can give advice on anything if you’re thinking of upgrading to PRO versions of any plugins.