hello,

to prepare for gate examination, you first have to focus on your undergraduate course, the basics are same as in the course and the exam.

still if you want to prepare for the exam from now, you can start solving made eay/RS aggarwal books for aptitude , maths and logical ability . these books will surely help you.

it's too early to join coaching for the gate, the coaching centres take admission only in 3rd year or 4th year of the UG course.

hope that helps