Hello student,

Looks like you are preparing for NEET for the upcoming yrs so all the very best. 

Coming to your question, firstly don't panic n be stress free looking at a bulk coarse of biology because once you start it will be easy for you. Focus mostly on NCERT. Thoroughly go through the book line by line. Give more importance to ecology and human physiology. 

For better remembering make flash cards and your own notes that you can look at the last moment . note down or highlight the imp points. Most importantly do as much as previous yr questions and give online tests . you can also set time and solve questions to improve your time management skills.lastly stay focused and all the very best!