Ok my Macos is working... but i have an issue i partitioned the drive to 10gb and left the other 30gb free space... because i want to install windows xp on the rest... but heres my issue... i need 10gb more for some parrallels stuff... so how can i add a partition in that free space? i thought i could do it via disc utility without even needing to reboot but apparently not... i cant add partitions or anything

find a windows/linux boot disk so you can get to diskpart. by using the boot disk. partiton your free space. reboot to mac. go back to disk utility and format the partiton.
and away you go