Salesforce trailhead offers fun way of learning any salesforce associated products. Unfortunately, Marketing Cloud does not have free trial org for learning purpose. Playground is also not available in trailhead. Alternately, we have one way of getting trial org for learning purpose irrespective of your company. We have trailhead academy. Register for any of the bootcamp and you will get access to explore more on the platform for specific number of days. Learn more: https://trailheadacademy.salesforce.com/all-classes#f-products=Marketing&f-siteLanguage=en_US For many years, this is part of Ideaexchange. Due to non compatibility of the platform with other platform for trial purpose this is still not developed and idea has been archived. https://ideas.salesforce.com/s/idea/a0B8W00000GdfIrUAJ/exacttarget-developer-edition?_ga=2.136982640.1559255416.1725565850-519232209.1688739681