I used Info template from site library, unable to show related posts in category

Hiya,

I impetrated Info template from site library along with demo content and then deleted the demo content. All my original blog posts are showing fine on site and looks nice.
I have 6 categories on my site, I went to Pages in WordPress admin panel and then selected Front Page from there, it shows all the content of my site, I renamed the demo categories name with my own blog categories, however my question is how I can show related posts to the related categories.

I watched so many videos on YouTube instead of asking here for help, but no one has clearly said how to do that. That's why I opining a ticket here for help.
Please help me, so that I can set my site, right now it shows posts on my site by default and not relevant to the categories :(

I do not know if I am allowed to give my site link here, so that you can have an idea what I am talking about because its hard for me to write in words here as English's is not my first language and I hope someone has understood my question and will be able to help me.

Awaiting your kind answer.

Cheers