Online marketing can assist very much set up a website with SEO and use GMB google my business and AdWords. You will definitely get clients 

It depends mainly on who you are trying to reach and where they hang out the most online. The type of content they enjoy most 

I would recommend that you join a business networking group, like a business chamber where you get to meet new people at regular networking events. This is how you would start to build business relationships with other business people. People do business with people that they trust. Even though the people that you meet at these events might not end up as customers of yours, remember that they have other networks and will tell others what you do (IF they know you and trust you). In effect, the people that you connect with end up being your "marketing team"!!