Before you go hire a business coach or sales person, enrol in an online course, follow a get rich quick scheme, do this first. Warning, this is a long list of things to do. No easy answers, no quick fixes, but the bare minimum of what you need to do before looking for more help. Remember, people hire who they know, who they like and who they trust. So time to get known.
Agile is an iterative approach to project management and software development that helps teams deliver value to their customers faster and with fewer headaches. Instead of betting everything on a "big bang" launch, an agile team delivers work in small, but consumable, increments. Requirements, plans, and results are evaluated continuously so teams have a natural mechanism for responding to change quickly.
Proof of concept in software development is a controversial topic. The person that came up with a software idea is usually convinced of its relevance. And stakeholders usually don't want to spend time on something that is not even going to be included in the final product.