Hi, 

You can definitely prepare at home through online coaching provided you can remain consistant. 

With online coaching its just you and the computer screen.. So if u do focus completely u wnt understnd much and there will be more doubts dt hvng clear concept. 

With classroom teaching comes the advantage of teacher student interaction,immediate doubt clearance as well as there are less chances of loosing focus.

So it depends on u.. Both are beneficial but thing is you have to choose the one that dt suits you and ur learning habits.

Regarding books first stick to the standard books like NCERT and one other standard reference book.(for all the subjects)

Solve as many questions as possible(can go for books lik GRB, Arihant, MTG fingertips etc)Join online test series. They help brush up ur concepts.

You can go for apps lik gradeup etc where u get daily quizzes. They ll help built confidence. 

If u have made up ur mind to take a year drop, then u need work really hard with dedication and consistency. And have fauth in urself.

At the end of the day u r master of ur future.

All the best