how can i study Chinese effectively?

Unfortunately, there is no other way than "Spending much time". No matter what kind of language you are learning, we just have to practise listening, speaking, reading and writing every day, in all your freetime.

As you studied for one year, I think it is time to do the HSK1 exam, and HSK2 exam.
You need to know all the material of the HSK1 and HSK2, do the exercises in the workbooks, do a lot of past exams. You also need to practice writing words each lesson. Listen to the audio many times.
There are apps to practice each word and have many sentences. Practice repeating each sentence many times, while reading the pinyin on top of the Characters. The app needs to correctly recognize your pronounciation. If it doesn't, repeat the reading again.
You need to study with a teacher in addition to putting a lot of effort on your own.
I have written many blogs sharing tips about learning Chinese. Please read them :)
https://serenezawaydeh.blogspot.com/2025/11/sharing-tips-about-studying-chinese.html

answer the following questions:
1. do you have a teacher to guide you? to regularly assess your skill and give you appropiate task according to your level?
2. do you have a regular time to practice your 4 skills: writing, reading, listening and speaking
3. In my opinion, finding a good teacher to help you in the early learning is very very important, otherwise you are mostly likely will stuck at certain level.
4. I am also from Indonesia and been teaching for couple of years, chat me if you are interested.