A multipage drupal8 website with my own customize theme

I am very new in drupal. I want to make a website with a drupal8 customized theme, that will be like my website, so that I can add anything any time very fast. So basically I have to make a drupal 8 theme by my own. I have already gone through some documents where I got to know to make a drupal 8 theme from scratch. I made that thing but for twig code I got confused. That is like what are the name I’ll give the contents and how I’ll write the twig code.
Is there anyway to make a readymade website to convert into a drupal 8 theme? Because I didn’t find any documents to convert website into a drupal 8 theme. If anything is there then please post the link otherwise simply help me to make it.
If I have to make it from scratch then what I have to do tell me in details. Otherwise suggset me what to do? It’s hard to find a theme according to my wish.

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