This study evaluates TeacherServer, a generative AI platform for educators, focusing on its effectiveness and usability. Using the Teachers' Acceptance of AI in Education (TAAI) framework, it assesses teachers' perceptions before and after workshops with 148 K-12 teachers from Florida. Results show a notable improvement in teachers' acceptance of AI tools, including increased perceived usefulness, ease of use, self-efficacy, and reduced anxiety. The System Usability Scale also indicates high usability for TeacherServer. The findings highlight the role of professional development in promoting AI acceptance and suggest future research into its long-term impact on teaching practices and technology integration.