I'm in the process of writing a blog post on investing as a student at the moment and would be happy to send it to you once published.
Short answer - it depends on what you need the money for. My advice would be to invest everything you can in low-cost passive index funds using the Vanguard platform.
This, for me, is the best mix of returns, low risk, low maintenance whilst being well diversified in a reputable, easy to use platform.
The earlier you invest, the more years you will benefit from compounding and starting investing now will create a really great habit going forward.
Generally speaking, investing in the stock market should be a long term pursuit (particularly using the method I laid out above) - if you're not willing to invest the money for the long-term, I wouldn't invest it.
It should be noted, once you invest, you can always sell and gain access to the money (usually in as little as a couple of days) so it's not truly 'locked away'. You do risk selling in a negative fluctuation of the stock market however and losing money which is why holding for the long term is advisable.
I'm sure your 30-70 year-old self will thank you for investing whatever you can as young as possible!
Good luck and let me know here if anything unclear!