Since you have not mentioned the names of the entrance exams you mean, our answer will have to be a generalized one.
Preparing for entrance exams can be simple.
All you need to do is know which entrance exam to prepare for.
There is many a good website on the internet presenting information, advice, tips, blog posts, notes, links, and videos related to entrance exams which can be gone through and utilized.
You can get all information regarding an entrance examination from one such site, and know everything – from exam dates, eligibility, syllabus, to how to apply, and more, and simply follow the guidance.
You can also join tutorials or find tutors to prepare yourself for the entrance exams that you want to crack.
All the best!