You might be too old now in order to easily learn how to trade. It is best to do so when you are around 15. However there are many sites which will provide you with a good overview of the topic:
http://stockcharts.com/school/doku.php?id=chart_school
I don't know similar ones written in Indonesian/Acehnese (Aceh Merdeka?) to help you understand better.
If this was a few years ago, I would have suggested going into Bitcoin. Now my recommendation is to invest in STEEM... I am doing so. You should invest in something that you know. About 15 years ago, I was connected to the computer industry and a person asked what he should invest in. I mentioned a specific graphic card manufacturer and he made a very good profit.
There is something called insider trading (illegal) where the owners of a company - people on the inside - buy and sell their stock because they know information that other people don't. While I am not inside the STEEM development team, I can evaluate things like how many people are join STEEM (over 500,000) and the rise in the price of STEEM
STEEM is something that I can participate in and research information about ... while Bitcoin (BTC) is now being bought and sold by people who don't understand it.