Some things like management principles, accounting, and others could be better learned in a short course instead of learning the hard way. In a struggling startup, a mistake like that could mean success or failure.
i've done all of those, and I can tell you first hand ... learning is best by doing ... it's not comfortable .. but you figure it out .... pass the accounting to an accountant ... or theres tons of 101 courses on youtube ... management itself is learnt by doing ...