Download an iTunes in pc, then connect your iPod to pc and running iTunes, you can move your music from iPod to pc though iTunes first. Then, you can transfer your choose music to your ipad. If it didnít work, pls try the tool ipod/ipad to computer transfer , its very convenience to solve the problem.
How to transfer iPod music/videos to iPad on PC
How to transfer iPod music/videos to iPad on Mac