How do you find initial clients before building a SaaS?

Hey guys,

I want to build a SaaS. I think the right thing to do it is to interview a few business owners and to find some pain problems that I can solve with a SaaS. So after that I can start working on the project.

First of all - is this the right approach? Or should I maybe come up with some idea and then contact businesses if they need this? And then start working on that project?

And second of all - how do you approach cold business when there is no established trust (I.e - I am working as a web developer but I don't have any portfolio projects so I can establish trust with the client).

I want to build a SaaS for the US market but i am from a small country in Europe. Do you think this is a problem too?