How can I upskill myself better to become a PMM

Hi there! I understand this is not exactly about being a PM , a little background - I've done some Comms/ branding work in some big name companies & startups, I have the inclination to learn and understand how PM works and wanted to understand if there's any course/ bootcamp/ project I can take up to apply for Product Marketing Manager roles? I have 4yoe in various roles. Thanks!