What do I need to learn from www.w3schools.com to build my own search engine?

What level of knowledge to you already have for web development? Are you just starting? Have you made web pages before?

If you are just starting, you might want to start a lot more simpler than building a search engine (this is an enormous project). Just try making a simple hobby site to start with.

If you are looking to develop a search engine for an existing site, you can actually use Google and place a Google search on your website which will yield only results for your site (or the entire web depending on what is selecting as an option by the user).

At any rate, more details are needed to help you completely.

You would need to build a web crawler that reports back and fills your database, that's something you wonlt learn from that (excellent) resource site.