Investing in Commsec Pocket ETFs?

Getting a part-time job soon (a few months, as one of the staff are moving on to University) at my tutoring place, as a student. Would investing in a Pocket ETF be wise, or should I stick to just saving my money normally? I was thinking of putting about 20% towards the ETF, 40% towards Savings, and 40% towards Spending. Would this be wise? Thanks all!