Its the best option for a newbie to start trading with the small amount and learn crypto trading first and after that invest, big amount because of you invests big in the start and loose while learning then you will have nothing to start again.
I suggest you to invest it in altcoins as your starting point since even you aim to buy bitcoin seems your budget or savings couldn't yet afford bitcoin though it is in low price. Better to try to invest it in aktcoins like ripple and ethereum since this two altcoin has a good status too in the market and also good coin to trade off too.