Hii!
It's never late to start something. So, don't be depressed. Just change your lifestyle a little and put in some positive vibes. Two years a re sufficient to prepare for the exam and you are not late. The age limit for the exam is from 21 to 30 years of age. So, you are eligible. Just dedicate yourself fully to achieve this goal.
Also, practice meditation and exercise daily. This will help you feel refreshed and boost your brain cells. You will be able to concentrate well on studies. Eat healthy. Get proper sleep, get up early. Change your daily routine and focus on studies. That's it.
You need to gain confidence in yourself. Believe you can do it, and nothing will be impossible.
Hope this helps.
Good luck!

Hi

Minimum age required to be eligible for SBI PO is 21 years and you are only 20, so you are not late at all dear to begin your preparation .

And yes you can definitely clear SBI PO examination in 2 years even if you start from scratch , for example ,there are many people who clear SBI PO examination in their first attempt and that also in the preparation of just one year, you can do the same all you need to do is remain honest and dedicated towards your preparation

For your English you can go through following books and master the language

High School English Grammar and Composition by Wren & Martin.
General English by SP Bakshi (Arihant Publication)
Word Power Made Easy by Norman Lewis.

Follow the below tips to prepare :-

First of all go through SBI PO syllabus and its exam pattern

Go through the previous years question papers and see the level of difficulty of the question paper so that you can prepare accordingly

You can take help of video tutorials available free on platforms like YouTube as well

Go through newspaper daily for General Knowledge and current affairs

Once you are done with syllabus go through mock test and identify weak areas and work on them

Thank you