How can I reach out to early adopters for my product?

Since you're newly launching, you need to put the word out there to your target audience. You must already have an understanding of who your target clients are and what they really want, think about what kind of communities will they be a part of or what kind of interests they will follow on social media. LinkedIn can serve as a great platform for reaching out to your target audience and start building a brand image. What you can do is you can post content that is useful to your target audience in relevant groups and even just search for them through LinkedIn search and you can extract their email information through a chrome extension named Aeroleads, it is what I use for my business. When you search for your target audience, make sure to use search filters to produce relevant results. The email information that you will extract using the chrome extension will allow you to reach out to them via bulk emailing and make them aware of your product launching. All the very best!