In order to gain access to Microsoft Dynamics 365 for Operations, you need to be either a Microsoft partner or customer. To sign up for a gain access  as a partner, you can refer to Lifecycle Services for Dynamics 365 for Operations partners at https://docs.microsoft.com/en-us/dynamics365/operations/dev-itpro/lifecycle-services/getting-started-lcs.

To sign up for a subscription as a customer, refer to Lifecycle Services for Dynamics 365 for Operations partners at https://docs.microsoft.com/en-us/dynamics365/operations/dev-itpro/lifecycle-services/getting-started-lcs.

You will need to download or deploy a Dynamics 365 for Operations development VM in Azure. To run the VM locally, you will need at least 100 GB free space available and a minimum of 12 GB free memory, ideally 24 GB. It will run on as little as 8 GB of assigned memory, but the performance will suffer as a result.

The official system requirements are as follows:

• System requirements (https://docs.microsoft.com/en-us/dynamics365/operations/dev-itpro/get-started/system-requirements )
• Development system requirements (https://docs.microsoft.com/en-us/dynamics365/operations/dev-itpro/dev-tools/development-system-requirements)