This is a common question that I've seen and answered before. You are not alone!
A simple way to validate any startup idea is to put together a landing page and drive some traffic to it. Unbounce is a great tool for building landing pages.
Spend a few hundred dollars on Google Adwords to drive relevant traffic to your page to see if you can generate leads for your service. When you generate some leads, get on the phone with them and pitch your business. If they are interested, you can let them know you will be launching soon and you will notify them. If they aren't interested, it will help indicate if your idea is something that people want.
For a few hundred bucks, and using a simple landing page, you can generate sufficient data to help you understand if you are heading in the right direction.
Another tool I like to use is Survata. With just $100 you can get 100 objective survey responses from your target audience.
I also wrote a blog post about how to validate your idea. You can check it out here: