Ever since Facebook opened up its platform for ads, a ton of advertising dollars have shifted to Facebook Ads. As a brand, if you are not advertising via Facebook, then you are losing out on relevant traffic / leads / sales.
To get started with Facebook Ads you need to learn the ropes. Head over to facebook.com/business/learn and take up all the free courses they have created. If you are serious about Facebook Ads, then you should take their Core Advertising & Planning certifications. Once you have a little knowledge of how Facebook Ads work, you can start promoting your business on Facebook. I'd recommend the following Ads to start with:
1. Page Like campaigns: Get more people to like your Facebook page. Make sure that you have created a custom audience of emails that you have collected. Using this custom audience, build a lookalike audience and target this audience for your page like campaign.
2. Boost Posts: As I've said earlier, the organic reach for Facebook has reduced to less than 1%. You need to pay to play i.e. boost your posts to reach your audience. Pick up the best performing posts by looking at your Page Insights and boost those posts to people who have liked your page or to other audiences which might be relevant
3. Traffic or Brand Awareness campaigns: With Facebook, you can launch campaigns for achieving different business objectives. I'd recommend that you start with Traffic to website campaigns or Brand Awareness campaigns before you choose any other objective.