you need a couple of wins...
my proposal is that you do this in part wb in the simplest way possible with primitives and move those around.
it is not an efficient way, but once you get used to some of the features in the program you will start to get the sense
that you actually can create something at least.
tutorials are not a bad thing, it is if nothing else a time and frustration saver when all things come about
go through the following tutorial https://forum.freecadweb.org/viewtopic. ... 37#p462576
(download), that should arm you good enough to be able to make the whole thing in part wb with primitives and just manipulate the placement of those.
then look at the attached model, make L-bars of different dims (overlong), copy those templates (simple copy), then place them to build the structure, cut the ends with cubes that you have to position as well, at last you can fuse them (and set property refine) to get a nice and smooth structure.
we all have different ways and paths to learn,
I suggest that you stay away from sketcher and partdesign wb until you can do primitives in part wb and position those where you want.
some people like manipulator wb for moving things around, but you can do just fine without it, using transform (right-click on the feature in the treeview) to begin with as the basic means to move things around, then there is also placement and alignment in edit menu (I would stay away from at least alignment until you are comfortable with the transform tool).
rage quit #2
, still some to go...
there are all sort of smart ways this could be done that are more efficient, but learning is not always trying to be as efficient or smart as possible,
it is better to learn the basics from ground up and build on that, then the efficient and "smart" ways is less frustrating to get acquainted with.