Problem customizing header on HB Highend theme

I’m having a very hard time customizing the header of the HB theme I purchased – I bought Highend and currently trying to customize the “Simple Blogger” theme. Here’s what I’ve been trying to do through Visual Composer and the WordPress platform. I just want a simple sticky (non-moving) header that has my logo, title, subtitle, and a one sentence mission statement. So far, using various options, I can choose header layouts that move my logo from one area to another, but I can find no options anywhere to add a text box in the main front page header area. I tried to “add a row” through visual composer – it will add a row BELOW the header, but not in the header itself.

I am a non-profit organization trying to help people and don’t have any money to hire an expert. Perhaps you could point me in the right direction? I love your Simple Blogger design, which is a nice clear user-friendly design for my audience. I would really appreciate your guidance on this problem. I am stuck for now.