[baccheion]

Outsource as much as you can (except the financials/accounting, unless you can find a trustworthy accountant).

Your first hire should either be someone that complements you, or that does your job (redundancy/"fault tolerance").

If you've managed to survive without a co-founder, then keep going without one. If someone ends up with enough responsibility to be the equivalent, then make them COO, CTO, CEO, or something along those lines.