it’s essentially a stripped-down twitter. so basically the bottom-right “plus” icon is where you can make a post. there are icons on a post that you can mess around with as well such as the like and repost buttons.
you can find featured posts and users on the “explore” page on the top bar. on that page, you can also search for a specific user or even a specific post based on its content
in addition, you can customize your profile by clicking on the settings icon on the top bar