U can look at Angel.co or u can read this
https://medium.com/@chris_boucher/top-10-best-online-platforms-to-find-an-investor-for-your-startup-b7c1ac38a5b7

1.Think About What Excites and Energizes You
This one's the first obvious step—we all want to enjoy and actually like our careers. (Perhaps the biggest sign you're on the wrong path is if you dread talking about your job.) While passion isn't the only requirement for being content in your career, many would say it's still essential, if only because passion is what keeps you going even through the tough times.

2. But Also Keep in Mind What You're Good At
Maybe you don't feel that passionate about any specific career—or you love multiple areas and can't decide on just one. Then it's time to think about your personality and focus on the skills you have. "Don't do what you love. Do what you are

3.Use the G+P+V Formula
The perfect career for you would most likely fit the G+P+V formula, which stands for Gifts + Passions + Values. Consider your strengths and passions, as we've noted above, and your values—what's nonnegotiable about the way you work?

U are on the right path if u have the 3 point based on the above formula

Do u know Sensational Marketing Campaign? that's what i called it !
Example: Build The Largest Handbags on Guinness worlds Record or the most Valueable Handbags with diamond/sapphire/diamond on it .....etc
Result: your Brands will get covered up by media around the Worlds!!!
You can Boost your campaign with PR to expanded Your Brands

You can Validate your idea with free and paid method:

Free Method
- Post your landing page to forum that related with your product category example:Product Hunt ,Hackers News is ok i think

Paid Method
-You can run ads on Facebook ,Twitter and google Ads with your Coming Soon landing page

or you can run your project on indiegogo and kickstarter to validate your idea plus get your financing if reach your goals