I'm new to WordPress. I installed a new theme and there was no content on the page, then I imported demo data, my database got populated with a bunch of content and there are now many different sections added on the homepage (for example this: https://i.imgur.com/2wmuJJZ.png)
I don't understand how can I delete this content and add my own? I tried deleting almost all .php files from /themes/my_theme and wp_posts from the database but this content didn't change.
If I wanted to delete this 'Who are we' section how would I do it and add my own?