Dear,

First learn the basics and choose a right person to guide you through preparation stage. The subject areas from which questions are asked in MH-CET are Mathematics, English, Legal Aptitude & Logical Reasoning and General Knowledge & Current Affairs.
For thorough preparation, one needs to start preparing at least 6 months before the exam date. For the exam preparation, one can join a coaching institute or can go for self-study with right study material and guidance.

Read daily a good newspaper because it helps you in GK and English. For maths and reasoning practice from a standard books. You should solve last year paper and gives a lot of mocks in your preparation stage.

Hope this helps!