Wire under the hood is the primary power to your amps. If you have more than one there should be a power distribution block in the back with 2-4 fuses.
Generally speaking a 30A fuse is under the hood if you're running one or two small-medium sized (~100W RMS @ 12V) amps. A larger fuse or multiple fuses if there's larger amps with heavier current draw.
What's the problem you're having?
You that nigga but I bought the car and the guy told me that I needed fuses for the audio and then he showed me the sub in the back and the under the hood wire. Basically I need fuses and to connect the shit
IF I keep it