How do i create websites like this?

Hi everyone,

I’ve just started learning how to convert html and css to wordpress.

My question for the day is – How do i create websites like these?

https://themeforest.net/item/gusteau-restaurant-wordpress-theme/full_screen_preview/409126

Basically, I’m looking at the nav bar at the top, and a big photo solider in the center, and the rest of the content in small boxes below.

Anyone can point me to any websites that have tutorials to build such sites?

Much appreciated!