By default there is a paragraph block on the new post screen. You can add more blocks using the blue plus sign in the upper left corner, next to the WP logo.
I added a separator and made it full width. Also a new paragraph to say this. Next I’ll insert an image, open the add block menu again blue +, use the image icon under the media heading to add a photo from the media library.
The gap above is simply a spacer block. You can resize it too.
This is a WooCommerce block of the best selling items. You get the idea. There seems to be a lot of blocks to explore in the WP editor – no Elementor needed.
Be careful – the next trick is kind of meta. When you click a block the edit popup is displayed as in the picture below. Click the down arrow tip (V ) and a drop down menu appears. I think you will like the inline image command. When you click an image block you get image controls like cropping.