> Talk to real customers (after reading the book).
That's good advice if you already have customers. OP seems to have the problem of not having customers.
That is the only advice if you have customers or not. Talk to the market. Find out if they will buy. That is why OP needs some basic sales skills (clearly lacks them).
Sales is the solution to the problem of not having customers.
Also, disregard any opinion that gives feedback on your site or product. Talk to real customers (after reading the book).