from where to study for pearl academy entrance exam 2020 online mode

You haven't mentioned the course which you are applying for. However, the admission test in based on General Proficiency Test, Design Aptitude Test and Media Aptitude Test. It depends on for which course you are giving the admission test and have to prepare accordingly. Here I'm giving a general idea on how one should prepare.

General Proficiency Test consists various parameters like Quantitative Ability, Data Interpretation, Basic Mathematics, Logical Reasoning, English language, etc. You can practice these aptitude online. There are various sites on internet, where you can get to practice these. Basic Mathematics like that you have studied in your class 9-10, that you have to practice. Arun Sharma's How to Prepare for Data Interpretation is also good.

Design Aptitude Test will evaluate the power of observation & imagination, communication skills, sensitivity to the environment, creativity, drawing and design ability, etc. Here you have to learn about different lifestyle trends of national and International level. In this section, R S Aggarwal's book for design aptitude is great.
http://design.careers360.com/articles/best-books-and-study-material-for-nid-dat-2019-preparation

Media Aptitude Test contains topics like creative thinking, visual expression, command over language and power of observation. Best book for preparation- Journalism and Mass Communication 2020. Read newspapers thoroughly.

http://design.careers360.com/articles/pearl-academy-exam-pattern