mytemplate.tpl not there (can i download?)

Hi everyone.
I cannot seem to change the template design. I have read through the posts here and people are talking about the mytemplate.tpl file, but I cannot seem to find it? Have I installed this wrong?

I am wanting to create a layout like this… https://www.fansclubchievo.it/images/esempio.jpg

Any help is much appreciated

Thanks

https://www.ads-software.com/extend/plugins/blog-in-blog/