You only need to focus on your class 11th and 12th Syllabus. In NEET Exam, questions asked from 11th and 12th class syllabus. So, You need to clear all your concepts without any doubt remaining.
Yes, Online classes are very good option. These are time savers and money savers. I suggest you to join PrepOnline. It’s an effective Online Platform for NEET Students.
Don’t forget NCERT. It is Must for the NEET Preparation.