You already have a great attitude of testing early and often! Keep up that mentality even as you gain traction in your business.
Think of your business as an infinite set of lego. You have access to every single piece Lego has ever produced and you can use as many of those pieces as you want. There’s no point in spending months building the Taj Mahal when what your users really need is the Sydney Opera House.
The problem is, in the early days, it’s impossible to know what that final product should look like. So, approach product development in a modular fashion with your lego pieces. Take five minutes to build an incredibly simple structure, like a square house with a flat roof and no windows. Give that to your customers, or potential customers, to use. Then, most importantly, gather their feedback. Maybe it’s totally wrong and you need to start again. Maybe you just need to change the colour of some of the bricks: that’s easy enough, you can just switch them out. Maybe you need you to add a pitched roof.
The point of this metaphor is that you should identify the smallest, cheapest, easiest product that you can produce for testing purposes and get feedback before you fully production-ize it. And once your product is truly in production and you have active users, you should continue integrating feedback and adding and removing pieces based on that feedback.
The “Thursday” and “Friday” chapters of the book/process “Design Sprints” has a great rundown on how to “fake” a product in Powerpoint/Keynote solely for the purpose of getting feedback from your users. The book itself is worth a read, but you can get a lot out of just reading the resources and watching the videos on that link above.
Per Adam’s comment above if you can give us a little more context on your product/service/business, we might be able to give you more specific and actionable feedback on testing your product/concept.