removing category, next post, previous post from Boldr theme

I am using Boldr theme and had asked the question on how to remove my posts category which is named the same as the titles of my posts…..the category is right directly under the title and I would like to remove it.

I was told to go into style.css and add .postcategory {display:none;} but it did not work.

There is also a blue rectangle at upper top of my posts and I would like to get rid of that as well.

Also, if possible at the bottom of my homepage and posts there is the previous post and next post links…I want to delete them because when you click on them they actually do not take you to the next post etc…it’s all chaotic…anyway, can someone please help me!!!!

I would post this in the Boldr theme are but cannot remember how to get back to it.

Thanks !!