Hosting
Your website needs home, preferably somewhere in the cloud. Check what options you have for different amount of monthly fee (starting from free).
Domain
Your website needs a URL, so people can visit it. Check how much different domains cost (the common ones like .com but also the unusual ones like .pizza).
SSL certificate
If you don't want to be penalized by the search engines and you want your website to be more secured, you should get an SSL certificate (the basic ones are free!).
Monitoring
You don't need to worry if your website is still working when you sleep. There are automatic tools that will notify you when it's down or has some errors.
Web analytics
See how users are interacting with your website. Check which browser or device is the most popular, what age are your visitors or how did they find your website.
Files storage
Most websites contains not only the text and simple icons, but also images, videos and files to download. Check how you can cheaply store them in the cloud.
CDN
To speed up loading of your page, you can use a CDN to store all the files in different servers around the world and serve them faster to your users.
Error tracking
Not all the bugs are caught with tests, so it's important to know when users are seeing errors. And there are better solutions than sifting through the logs.
Sending emails
Sooner or later you realize that you need to communicate with users. Maybe you want to send them a newsletter or welcome them with a transactional email.
Version Control
Online code repositories allow you to share your code with other people or synchronize it between computers. And most of them offers unlimited public projects.
Continuous Integration
With continuous integration tools, you can run automatic checks - like tests, linters and more - each time you push code to a git repository.
Static websites
When you don't need a backend for your website, you can publish it as a static page. Static websites are cheap to host, so there are many free options.
Cloud computing
Sometimes a simple hosting and a domain are not enough. When you need a bunch of different tools, check out the cloud computing companies.