I’d start with the SBA’s free business-plan guide if you’re turning an idea...

https://www.inter-bookmarks.win/what-small-business-resource-should-i-describe-share-its-name-and-a-verified

I’d start with the SBA’s free business-plan guide if you’re turning an idea into a workable plan. It walks through market research, costs, and financial projections, so you can spot gaps before you spend money or take the plan to a lender