Before starting up, please do this:

1. Be crystal clear on what you will build for the next year at least. Of course it will change, that's okay, but be clear on day 1 what your thought process is on why the product will work
2. Talk to your future customers at length, understand their pain points, build personas. Think like they do.
3. Try talking to other founders or investors before you start. They can really tell you some very important things that you may miss out on, starting out
4. Make sure you start it with someone. And that person is as committed, you know them at least for a few years, and you have unique skills that complement each other

I hope you will consider this. I am 1.5 years into my journey and realize some fundamental mistakes I made that have costed me. I don't want you to make the same ones.