Runs Go on all platforms.
But it must first be compiled for the required platform. For example, you can compile code on Windows to work on UNIX systems. This is done using environment variables. In many cases, preferences give Ubuntu and CentOS always better to install fresh ones.
If you write your server then Nginx is not needed. But if you want to use a router or a load balancer, then of course Nginx will help. But we must remember that Nginx has its charms.
Database is a matter of requirements. It all depends on the tasks and speed requirements. Need the highest speed is Redis , if you need a web service - MongoDB or RethinkDB. Of course, no one has canceled wonderful MySQL and PostgreSQL if you need a relational database or, for example, you are in love with triggers and stored procedures.