From the graphic you see how to connect the push button

Red : power
Green : ground
Orange : Button control
Blue : LED power

I connect the 5V to the + and gnd to the – on the left.  

The button has two pins on right side.   I made lower pin the + and the upper pin the -.

Push button sends a signal for pin 8 to go HIGH (ON) or LOW (OFF). 

const int buttonPin = 2;
const int ledPin = 8;
int buttonState = 0;

void setup() {
// put your setup code here, to run once:
pinMode(ledPin, OUTPUT);
pinMode(buttonPin, INPUT);
}

void loop() {
// put your main code here, to run repeatedly:
buttonState = digitalRead(buttonPin);

if (buttonState == HIGH) {
digitalWrite(ledPin, HIGH);
} else {
digitalWrite(ledPin, LOW);
}
}

Why a 10kΩ resistor on the push button?

The 10kΩ resistor is used to remove noise from the circuit and from damage to the device.   It is also a pull up resistor to reduce current flow.

Mark T posted this:
The higher the value less power is wasted, but the noise pickup susceptibility is greater, any value from
100 ohms to 10M can work, but the rule of thumb is 10k is adequate to protect against noise on-board (assuming a PCB with a ground plane). The pullup value must be >> switch’s on-resistance, and << inter-trace leakage resistance (those are typically 0.1 ohm and 10^9 ohms, so there is a massive possible range for pull-ups!!)