You'll hear the acronym MVP thrown around, and for most, it stands for "Minimum Viable Product", but I find that's often misleading. I like to refer to MVP as "Minimum Viable Proof" because I find with the former, people spend too much time focusing on creating some sort of product, when in reality, they really need to be gathering 'proof' that their potential solution to a problem is valid.
It takes a bit of creativity, but if you're able to identify your key assumptions, and the core value of your product / service, think of how you can obtain 'Minimum Viable Proof'. If it's going to take longer than a day, chances are you're not thinking of a true 'Minimum' Viable Product.
Learn the basics of product-market fit - your startup depends on it.
Progress over perfection.