I started a large SaaS Company for B2B where perfection in code is as importante as it gets.
So here is my advice, DON'T CODE until you know what the Saas Really is.

First start understanding what the problem REALLY is. Interview people and actually spend 100% of your time doing Customer Discovery. (This sounds easy but it is a skill you'll have to develop far more important than coding).

Once you understand what the problem is, come up with a value proposition. Still no code.
Then make a sell.

If you can actually find things already existing that you can Hack and put it together then use that.

Then make another sell.
If you can sell it to at least 50 people if you are B2C, or if you are B2B you should have at least 1 customer.
Once you do that then start automating some parts of the solution that you have hacked and so on.

But THE most important thing is to be in constant conversations with your customers and hot leads.

Remember you are a customer making machine not a coding machine, the first one is where the money is.

Hope this helped you, if you want to talk more about customer discovery and customer development, just give me a call.