I'd go with "finding the right business model" - also known as finding product market fit. You have to go back and read this legendary essay - https://www.linkedin.com/pulse/marc-andreessen-product-market-fit-startups-marc-andreessen
Product-market fit above all else. If there is a demand for your product and people are willing to pay for it, that momentum can be used to fuel all other journeys - the journey to build a great team, the journey to build a great culture etc. but nothing succeeds like success and early success is the best success. A successful entrepreneur is rewarded disproportionately for finding product market fit, i.e., for the risky job of giving up whatever you do to bring home a paycheck and go hunting for that space where there is a market need that is aching for a product / service. Before you go from farmer to a hunter, make sure you are in a place where there is some big wildebeest, then show you can bring home one or two of them. Once you do that, you won't have a great deal of trouble finding other hunters to join your mission.