The Emacs mode for programming in Ada helps the user in understanding existing code and facilitates writing new code.
When the Gnu Ada compiler GNAT is used, the cross-reference information output by the compiler is used to provide powerful code navigation (jump to definition, find all uses, etc.).
When you open a file with a file extension of .ads or .adb, Emacs will automatically load and activate Ada mode.
Ada mode works without any customization, if you are using the GNAT compiler (https://libre2.adacore.com/) and the GNAT default naming convention.
You must customize a few things if you are using a different compiler or file naming convention; See Other compiler, See Non-standard file names.
In addition, you may want to customize the indentation, capitalization, and other things; See Other customization.
Finally, for large Ada projects, you will want to set up an Emacs Ada mode project file for each project; See Project files. Note that these are different from the GNAT project files used by gnatmake and other GNAT commands.
See the Emacs info manual, section 'Running Debuggers Under Emacs', for general information on debugging.