I'm In TY and i want to get ahead in maths we are doing barely any... Can you help me with which books i could get or which topics i should focus on? I intend on doing physics and applied maths too
Buy yourself some exam papers! Work through them and you'll be ahead in no time. But don't put too much pressure on yourself as TY is a year to relax before all the leaving cert stress. Whatever you do in TY will be revised in 5th year anyway so don't worry too much :)
Revise the basics, and get really really fluent with Number and especially Algebra topics. This will stand to you in 5th year and beyond.
If you are weak at any area in the course, use the time to get yourself up to speed. Better to be decent at most areas than to be outstanding in one area and really struggling in another. But having said that, fluency in number and algebra will always be an asset.
If you are really strong on lots of areas, and as you say you want to get ahead, then you could start looking at new material, including calculus if you like. But only if you are rock-solid with the JC Higher material.