Well one way to learn is by shadowing someone who already knows how to do something.
To be fair if you are not really sure how to design this properly for it's intended purpose then you could end up right in the s*it, this is why Rob was suggesting you seeking some hands on help.
As he said, installing it will likely be easy enough for you, designing it is something else completely different.
You are right we all have to start somewhere, usually we learned by assisting others who already knew what they were doing,and by learning why things are done certain ways, asking daft questions and the like
, nobody suggested you are a substandard spark in any way shape or form, sometimes it is better to know enough to know that we don't know enough if you catch my drift, there is no disgrace from asking someone to help you out, particularly if you are unsure.
Learning on the job and making mistakes with a 3 phase supply and distribution is not really the best way of learning though, it could seriously backfire and as I say land you in the s*it.