Without traffic (visitors) to your website there’s no reason to have one.
Most traffic comes from search engines, social media, referral links and advertising.
The better quality content you have on your site, the more “free traffic” you’ll get. Search traffic, social shares and people linking to you.
Advertising is a different animal and it’s easy to waste a lot of money before you figure it out. We won’t touch that for now except to say stay away from anyone promising you “traffic or hits”.
Don’t buy hits or traffic, it will come back to bite you.
So the simplest way to get more traffic is create great seo-friendly content and convince people to share it.
Here’s something to think about.
You could spend $100 in advertising and you might get 500 visitors to your website and a few sales.
However, if you paid $100 to a expert SEO writer you might get 500 visitors a month (indefinitely) from their article. If I could go back in time I would have hired more great writers to create viral content for my site. Check out Upwork.com for Expert SEO Writers, it will pay more traffic dividends than almost any other resource.
This won’t happen overnight, be patient.