How to power an LED stripe and the Arduino Nano with the same power source

Schematic looks basically OK except for the speaker part - I assume this is a sound module that's powered separately, not just a speaker as drawn?

The LED strip has its built-in driver I assume?

Those Fritzings are like a cancer. It's all over the place. The other day I was looking for some schematics and it took me ages to find a readable circuit diagram... all Fritzy images. Sure it looks pretty but it's not a way to build a circuit beyond two or three LEDs.

Your schematic is pretty readable:

The protoboards aka stripboards aka perfboards we're talking about looks like this:

The end result can look a bit messy, though. That's what always happens to me... Step 1 is build your circuit on solderless breadboard, then when it's correct you solder it on perfboard. I'm using the PCB layout function of KiCAD big time to sort out all connections and where to place stuff before starting to build my protoboards.