Adding Blocks in Templazee Theme is same like adding block in any other WordPress theme. You can add WordPress inbuilt blocks in the page or posts.
Simply go to page or post you want to create, When ever you see the ⊕ you can click on it and get a list of blocks, in a little modal window. On top you see the ‘Most Used’ blocks. You can scroll down and open up other categories, like Layout, or Common, or Widgets, and find more blocks. In the inserter window you also find 3rd party blocks from installed plugins.