1. Software
Sound effects and music are all produced with audio software, including Nuendo, Cubase, and Logic. Sound source plug-ins can be downloaded from the Internet (eMule has many).
There are also materials online, which can be modified by nuendo. Since making music for games involves copyright, this article should be used with caution.
If there is a recording studio, it will be more professional. You can make some sound effects yourself, which are realistic and the effect is good.
2. Production process
This is difficult to say because different people have different production methods. For example, as mentioned above: it can be produced in a recording studio, or you can find materials for modification. Then just load it into your software and use your imagination to create step by step. There are many tutorials on how to use nuendo on the Internet, which is very easy to learn. It mainly depends on your ability to master music knowledge and your space to play.