How can I build a mixed-columns form in PHP using bootstrap 3?

I'm trying to make a 1 column form in bootstrap with some rows sharing a second column. It's for making an employee profile editing page in an intranet so I don't really care about medium or small screen sizes.

I'm trying to make it using an example I found here but the result is not what I need. I'm used to work with CSS style sheets but to be honest, bootstrap grid system always confuses me.

Here's a mockup of what I need:

Here's what I'm getting:
If anyone could give me an empty structure with a couple of lines so I can start from there... it would be awesome!!!

Thanks in advance!