There are various types of web hosting that you can purchase, for people who only ever want to host a single website, they can generally just buy the cheapest web hosting option, (which will cost you around $5 to $10 per month. You can add more domains to this type of account, but they will all point to the same website.
If you think there is any chance you may want to build more websites in the future, then your best bet is to get a “reseller” web hosting account.
Reseller accounts can be used to “resell” hosting to others effectively building your own hosting company, but most webmasters just use these reseller accounts so they can host multiple domains of their own on the web host account.
Reseller Hosting will generally cost you $20 to $30 per month, and you can host an unlimited amount of domains each with their own website.