HTML has the
<p></p> tags which is what contains the paragraphs for your website. Your content goes in between the tags and will be displayed on the site, typically with some margin and or padding between them.
<p>This is the first paragraph in the article.</p>
<p>This is the second paragraph in the article</p>
Paragraphs are used to help format your articles and should follow your standard grammar and formatting as if you were writing an article in an email, newspaper etc.
You can have as many paragraph tags as you need for an HTML Document. Just remember that the content must flow properly and be coherent.
Keep your paragraphs within 4 to 6 sentences and try to ensure your sentences are written in an active voice. This goes into User Experience and SEO which is beyond the scope of this tutorial but stay tuned for more on this topic.