I am a software developer and left my job 4 months ago to start a startup. I had the same fear as you in the beginning and to add to it, English is not my first

I am a software developer and left my job 4 months ago to start a startup. I had the same fear as you in the beginning and to add to it, English is not my first language! You will hear this advise again and again, people buy from people. Nobody cares how good you're in talking, they will focus on why they should buy from you. What is your story? and how credible you're. So I agree with @nickfromseattle comment. Go and build your personal brand first. Keep in mind, you're the best person who knows the product as it is yours. You can answer any question about it easily. Just go and start talking to potential customers, it will not be easy in the beginning but you'll enjoy the learning process.