To get started with Android ROM development for your Miva phone, follow these steps:

1. Understand the basics of Android: Start by learning the basics of Android, including its architecture, components, and development process. You can find plenty of resources online, including official Android documentation, tutorials, and forums.

2. Set up your development environment: To develop Android ROMs, you'll need a suitable development environment. This includes:

• A development computer: You'll need a Windows, macOS, or Linux machine with sufficient storage and RAM to run the development tools and emulators.
• Android Studio: Download and install the official Android development IDE, Android Studio, from the Google website.
• Android SDK (Software Development Kit): Install the Android SDK, which includes tools and APIs for Android app development. You can find the SDK within Android Studio.
• Android Platform Tools: Download and install the Android Platform Tools, which include the 'adb' (Android Debug Bridge) tool, used to communicate with your Miva phone.

1. Get familiar with the AOSP (Android Open Source Project): The AOSP is the open-source foundation of the Android platform. Familiarize yourself with its structure, build system, and development processes. You can find the AOSP source code on the official Android website.
2. Choose a custom ROM: There are numerous custom ROMs available for Android devices, each with its own features and community support. Choose a ROM that suits your needs and preferences. Some popular custom ROMs include LineageOS, Resurrection Remix, and AOSiP.
3. Obtain device-specific resources: For ROM development, you'll need device-specific files, such as kernel sources, proprietary binaries, and vendor image files. These can usually be found on the manufacturer's website or in the custom ROM's GitHub repository.
4. Build your custom ROM: Using the AOSP source code and device-specific files, start building your custom ROM. This process involves compiling the code, configuring the build system, and customizing the ROM's features. You can use the 'make' command within Android Studio's terminal to build the ROM.
5. Flash the custom ROM: Once your custom ROM is built, you'll need to flash it onto your Miva phone. To do this, you'll need to unlock your phone's bootloader, install a custom recovery (e.g., TWRP), and then flash the custom ROM using the recovery's interface.
6. Test and troubleshoot: After flashing your custom ROM, test it on your Miva phone and identify any issues or bugs. Fix these issues, rebuild the ROM, and flash it again if necessary.
7. Contribute to the community: Share your knowledge and experience with the Android development community by participating in forums, sharing your ROM, or contributing to existing projects. This will help you learn more and improve your skills as an Android ROM developer.

Remember that Android ROM development can be challenging and time-consuming, but it's a rewarding experience that allows you to customize your device and contribute to the Android ecosystem.