I agree with what everyone else is saying but would add a level of detail. I have spent 20 years developing and launching innovative technologies and business models in enterprise/B2B with some many lessons learnt. My key lessons would be:
(a) Having a product that the customer really wants (or has been actively looking for), that the buyer will pay/commit resources (time, personnel etc.), even at pre-product level. You can do this for both B2C and B2B
(b) Finding potential customer(s) that you build a relationship with where they give you a lot of feedback beyond the product because you need to understand the ecosystem you are selling into
(c) Knowing that the buying decision process and timeline in advance - ensuring that your buyer can get this purchase done
(d) Estimating 2x more for everything – double the amount/time etc for costs, delivery, decisions etc.
(e) Understanding that the stress and emotional journey levels are going to be very high and can be isolating. Free remedies include meditation, exercise and finding a group of people you can talk freely with about what’s going on
(f) Figuring out whether your risk and timing tolerance matches your product’s sales cycle
(g) Listening well and asking questions – reflective listening is really helpful with customers, providers etc.
(h) Don’t assume anything – sometimes the “pain point” or question you think you are solving isn’t so bad for the customer or that they frame it in a different way – be ready to learn all the time
(i) Read “the Lean Startup” - it is very helpful

You can do all this without spending hard cash but it takes a lot of time and patience.

Happy to jump on a call if that is helpful.