Scraping/embed links is taking videos embeds/direct urls from other anime sites and put it on your site. Animixplay is an example of an all-in-one scraping site. A magnitude of "anime streaming sites" these days are just "gogo scraper" which copy the iframe urls from gogoanime to put on their website (my website is a gogo scraper too).
HTML, CSS, JS is not enough for a website, you need to learn backend programming languages like PHP and you'll need a database to store your anime information, episodes, embed links etc... If you plan to create a HTML page for each episode and don't use any dynamic programming languages then it's the god-level tier of hard-work, conscientiousness and stupidity.
I suggest you to learn backend programming langauges/frameworks (or sth like that) like Nodejs (Javascript), PHP, Django (Python) (I'm using this) and learn about databases like MySQL, PostgreSQL and get an idea of how the backend work before even trying to build a streaming site.
The video player part is not very important, unless you want to run your own servers which is susceptible to legal troubles and extremely costly if you don't know what you are doing. I advice you for the time being, try scraping from websites like gogoanime and/or upload your anime content to websites such as streamtape, mp4upload, fembed and get the embed links. It is not be the best because of ads and buffering, you may consider building your own servers after learning more about legal risks and concealing your identity.
If you don't want to go through the hassle of learning backend, try installing WordPress with Dooplay theme which should provide you with a basic site for anime streaming although it comes with a cost of much less customization, however when experienced enough you can just tweak the source code to what you want.
Happy coding!