You don't need to set up a Facebook business page unless you plan on keeping up with it. Just setting one up and then never posting anything is worse than not having one at all, because if people search for you and find an outdated page they might think you went out of business. If they don't find one at all they might think you're just not on Facebook - no big deal!
Social media marketing is not something you should look at as a way to get new customers, it's more of a way to stay in touch with past customers. If you're just starting out, it should not be a high priority.
Here are some links you might find helpful: