Coincidentally I just bought a DAE MJ-50 turbine flow meter that looks similar to yours.
Firstly check that the model you are intending to use gives the resolution you need. Different models position the sensor over different dials to give a pulse every 0.1, 1, 10 or 100 gallons (378 litres).
The picture you provided shows the sensor over the 1 gallon dial which has 10 divisions and therefore will give a pulse every 10 gallons (37.8 litres). Is this resolution good enough for your needs? Check that the product image actually matches the model number which in turn will tell you the volume delivered per pulse.
On the DAE MJ-50 the sensor is a reed switch with 2 wires and is read the same way as you would read a mechanical switch using a pull up resistor and a digital input. If yours also uses a reed switch then pick a resistor value that limits the current to a few milliamps. Connecting 5v and ground directly to the 2 wires will destroy the switch.
Note that at very low flow rates the meter will not register any flow at all. You need a minimum flow rate to overcome the internal friction of the components.