1st pi project - advice appreciated

Hi

I currently have a pi b+ as my volumio 2 server and I will have a client in the next day or so using snap cast.

The next step is all new to me.

When done, I want to have a aluminium box with an LCD blue screen with a power button to turn on the server with a proper shutdown script and volume control.

I will have the current song playing on the LCD when finished too.

My first question is what do I need to convert from a kettle lead 240v to 5v (I am guessing 5v will be enough for the pi, LCD and buttons ?

Thanks in advance

Martyn