Cart is ahead of the horse. Getting out of the office to talk to potential customers has NOTHING to do with selling. It has to do with learning about the sector you THINK you want to be working in. In other words, you need to accept that your foundational knowledge is largely made up of information that made its way to you by going through your filter of preconceived notions and biases. My advice to my sales team (and to you) is to stop thinking about your needs (selling something, validating your product, etc.) and start thinking about discovering their needs. You do this by asking questions and listening.

People love to talk about themselves and their businesses. You will get a ton of positive response by picking up the phone (or sending emails) saying "I'm new to this sector and I've been learning everything I can online and through books and trade magazines. But I know I would learn more by talking to someone working in the field. Could I stop by Monday morning for 15 minutes and learn about your business. I'm interested in finding out how you came to even be in this business, what parts are enjoyable, and what parts are challenging. Thank you for your consideration."