*I would like to know how can I also list the blog previews (or teasers) on the home page*

You can do this using views in both D7 & D8. If you go at Structures/Views, you will find the view name `Front page`, you can enable that view which by default works as front page in Drupal. So as per you need, you just need to apply filter for `blog` content type and in view mode you can set it as `teasers`.

*as well as the main blog page?*

Same way you can make new view and give new path/url to that view and set it as `main blog page`.

**Edit:**

**D7**

> [![enter image description here][1]][1]


  [1]: https://i.sstatic.net/gqanC.png