if we only have small money, then we can buy bitcoin with small parts too. this is what I like from bitcoin, we don't have to buy 1 bitcoin in directly, we only need to buy what we need. after we buy bitcoin, then we only need to hold for a while and we need to make sure that the price is up then we can decide to sell our bitcoin to gain the profit.
The issue with that approach is that your profits are going to be small too, and I think it is very obvious that we want our profits to be as high as possible so you only have two options to learn how to earn more fiat or to learn how to earn more bitcoin.
Small parts buying can give you a low profits if you select to hold it for long period and I suggest that if you buy a small portion of bitcoins on these state and try to trade it on trading sites so that your small portion will grow and by the time bitcoins hits another pump then you can earn more money for that doings.
Trading can be a great option but it is not the first option that I will suggest to someone with a low amount of bitcoin because while trading seems like it is very easy the truth is that it can be very hard and you only need to make one mistake in order to lose a huge amount of money.