You have tp remeber that the rates you see is "per annum" rate.
I.e. for your example; it's 3% divided by 12 months - 0.25% interest per month.

In term of amount saved per month, it is enough at your age.

Try to learn more on investment, personal finance & investment vechiel especially Unittrust. There are online UT agents locall:

https://www.eunittrust.com.my/ or
http://www.fundsupermart.com.my

As you are only 18, u should invest in fund rather than park your mony in FD. Remember, DO NOT HOLD  a fund forever. Profit taking and rebalancing is always necessary in achieving your goal. Ofcos, you need to set a goal in the first place.

I am willing to tell more if you want to know more.

Definitely a good start if you re only a student now. By the time you graduate, you will have RM19200 in your bank account if you save for 4 years. If you don't want to wait till the fourth year, RM4800 in the first year is enough for you to buy into some chinese mutual fund that is highly potential, or even local small cap growth fund. Keep investing in the second year till the fourth you might have more that 25k.
Same opinion from me compared to above case from bubu, if you save RM400 every month.. you can see the difference...if you stick to your own house, you re RM25k++ poorer in the fourth year compare to bubu, assuming you are paying more than RM400 each month on your house instalment. And then you also lose to bubu's investment head start since 4 years ago.

Just my opinion..