What should i learn/ study to tweak my blog

Hi

I bought a product to create a blog very quickly without having to learn
CSS/PHP/HTML.
I have now realised that there is going to be no plugin or help available for how I want my blog specifically to look like. My question do i need to learn all three scripting languages above to do this ?

Ultimately I want each page to have 20 cube boxes instead of 10 long boxes (posts) on top of each other. Also learning what the hell the difference is between keywords and tags, relating to my blog.

I found w3schools extremely basic, but thats probably because I am familar with some programming languages allready.

Thanks ! ??