Internal linking refers to a link on a page that points to another page on the same website. Internal linking is important because it helps strengthen those keywords internally for those pages, it allows users (and search engine robots) to navigate through the website, and it tells the search engines that the page is relevant for that keyword phrase.
Your website needs a place to live on the web, and the quickest way to reserve your web address is to find a web host. There are a variety of cheap web hosting providers, and each one has a specialty. Look for a web host that offers a price that fits your budget, has the web tools you need to create your envisioned website, and provides support when you need help or have problems.