Hello,

First find an entrance exam you are interested. then go for syllabus part. Then start looking for resources. Like for basics,theory, numerical (if it is there).

Then you have to start learning it and by time you will learn it and able to increase your performance gradually.

There are mock test available for it. you can appear it and know where you stand and what is the weak position for you.

then improve your weak to a strong point and you will improve for sure and your performance will prove it in the results of entrance exam.

Hope it helps!