Guidance needed in creating a branch

[Colin Campbell]

As in the subject, I'm trying to get back into documentation work, after 
13-14 years or so. I've followed the CG section 3.1, to the point where 
I have a fork of master on gitlab, a clone of master on my local 
machine, and a local branch (ottava) with the edited file.

I see that developers have branches on gitlab, showing as 
origin/dev//username/; I gather that this is The Way It's Done®, but I 
can't find direction in CG as to how to create such a branch. Is it as 
simple as, e.g. git push -u origin dev/cpkc/ottava?

Any guidance  (and patience as I fumble through the process!) will be 
gratefully received, and I'll probably propose updates to the CG to 
capture your help.

Cheers,

Colin