You purchased a domain! Domain parking is basically doing nothing to your domain name. No website, just the name, free but no one else can purchase it. You now own intellectual property.
If you purchased a new car, you park it in the garage.
If you open a physical business, you get the keys and go to the address. With a domain, you need a place to put your domain and build your website. That garage is a host. There is a cost for hosting your site.
Web hosting is an online service that enables you to publish your website on the internet. When you sign up for a web hosting service, you basically rent space on a physical server somewhere and store all the files and data necessary for your website to work properly (compared to a building to put your business in). Without hosting there is no place to create a site.
Again with the research! There are many web hosts! Search 'host my domain'! What does the host offer you? How much does it cost? What is the length of lease? Picking a host may mean moving your domain to that site.