Everyone is an expert at something. The Internet can be impersonal - you must establish a relationship with your niche market. It's your most valuable marketing tool. I'm not talking about SPAM, which doesn't work. Share information with others.
Facts tell and stories sell.
Once you make that first sale, tell your story to others within your sphere of influence. People will be attracted to your success and will want to do what you do. Duplicate the success of others, If you want what they have in your life then do what they do. Another reason to purchase marketing manuals and courses. Develop some of your own ideas.