Hi,
i'm searching to build a nano sound player, need to be place in a little box 10x5x4.
I just need to play 4 or 5 sounds just pressing a little switch. every switch pressure will play the next sound etc.
Is it possible to build it with an arduino nano?
Thanks a lot for your precious help.
Regards
Yes that should be doable.
10x5x4 what? Feet? Millimetres? What sort of sounds?
If you only need sounds as simple as single tones (beeps) then you'll just need the Nano and a buzzer/speaker. Otherwise you'll need some other equipment like an MP3 player.
Steve
10x5x4 cm 
need to play mp3 files
Need something like DFPlayer Mini then. Should easily fit in your box with Nano and small speaker.
Steve
sounds good.
And do you know how to plug and setup the device to work with the switch?
I'm a super novice 
I'm not going to design your project and write the code for you. Round here we help people to do their own projects and get them working.
Try Googling "Arduino Nano MP3" and see if you can't find something there to get you started.
Steve