The idea is that I would be able to send an alert when water usage has occurred for longer than 60 mins continuously. (as well as providing water flow data).
According to the product page, the flow meter will run on 5V. In that case you can connect the output directly to a digital input on a 5V Arduino. Don't forget to connect the grounds.
If the sensor and Arduino must be electrically isolated, use an optocoupler.
Be aware that long leads between the sensor and the Arduino will pick up electrical noise, unless steps are taken to minimize the disturbance.
We strongly recommend that people start with the basics of Arduino, before tackling a moderately advanced project like this. There are plenty of examples included with the Arduino IDE (the software development package) and many, many more on line.
You should learn to read a pushbutton, blink an LED without using the delay() function, and time a pulse before starting with the flow meter.
If you want to pay someone to design your circuit and write code, ask a moderator to move this thread to the Jobs and Paid Consultancy forum section.
Note that the LED input on the flowmeter requires a current limiting resistor.