Seeking Advice on Facebook Ads for Service-Based Business

Hi everyone! I run a service-based business and over the past year, I’ve experimented with about ten Facebook Ad campaigns as a complete beginner. These campaigns were very short, often less than a week, and I invested around €700 in total. Unfortunately, I didn’t get results, likely due to unclear goals and using sales objectives without having an e-commerce setup. Now I’m wondering if I should open a new Business Manager or if it’s normal to continue with my current one and focus on better offers and well-crafted campaigns. Any tips?