Faulty battery or alternator? Weird issue.
 

So basically the other day I was driving after starting the car and the radio just cut out for a second or two, I thought ok this is strange, it happened again the day after, but not very often.

Then today after I turned the car off, the mileage reset back to 0 again along with the clock. Shortly afterwards the car wouldn't start, it appeared as if it had a dead battery, but after waiting about 5 minutes, there was power to the car again and it started.

What do you guys think it is? Battery problem? Or alternator?

Thanks in advance

Is the car throwing any check engine lights?

First I would check the battery there should be a production date sticker, typically a battery should be replaced every 3-5 years.

It sounds like it could be the alternator, typically its the voltage regulator on the alternator that starts failing first and these cars start throwing all sorts of faults when the regulator is not giving the car a consistent voltage.