The Dynamics 365 release plan (formerly release notes) for the 2020 release wave 1 describes all new features releasing from April 2020 through September 2020. You can either browse the release plan online or download the document as a PDF file. The PDF file also includes information about Power Apps, Power Automate, Power Virtual Agents, Power Platform governance and administration, and Common Data Model and data integration.
The Power Platform features coming in the 2020 release wave 1 have been summarized in a separate release plan as well as a downloadable PDF.