I have not done a complex project like this before, only small ones (tea cup, pan, oil drum, etc). How would I make something like this without the human inside, I am struggling:
The jump from “tea cup” to “intricate herd surface modeling with complex paneling” is substantial enough that I think you should do some in-between projects first. Maybe check out this tutorial: https://m.youtube.com/watch?v=ZNFu2VgQfJo as well as some other hard surface modeling tutorials, and practice making just some simple cubes with paneling and detail work. Once you can consistently make a cube look like that, then you can jump up to making a human-shaping object look like that
And do you have a video for the human one as well?
Once you have your hard surface modeling techniques (detailing, panelling, booleans, and bevels) down- on cubes- you won’t need a tutorial for this project. If you can do those techniques in your sleep, which you need to be able to do before tackling something so massive, this will be a breeze. You can use any human base mesh and make it exactly how you want it 
you can find a free human base mesh easily with google but please don’t yet. Jumping into this huge project without having the fundamentals perfect will make you miserable 
Recipe for cooking something like this,
lies in a mesh of a model which is pretty much nothing more or less than structure of the muscle.
Which is being separated in places where the muscles join by stretching planes as “retopology” or fixing things straight to the armature which is my best advice.
By pulling verts out of weight painted body, You wont be able to extrude them anywhere far but only use the mesh for purpose of building or modelling around of the bone from which the vert has been pulled or duplicated. And is pretty much enough to draw silhouettes by extruding single verts in order to look from the side or the front, followed by duplicating edges of lines in order to press F while two edges are selected to fill it with a flat face which is sort of the start of the process towards making your concepts.
And always keep in mind that by allowing a slight geometry in a single model pulled to wrap around a particular bone, can be shape keyed and work for making several different types while not being too heavy as it is just manipulation of position of existing vertices…
Then if You create animations of Your characters desired moves that You want it to make - by moving through the armature move reel and adjusting of pulled vert lines which contain weight influence of the moving bones will help You to see how much of space You’ve got for the shapes of the parts and if the parts are not colliding together and are okay for all of the moves and so on…
