1 . yes , you need to have the free space aftee the partition you want to grow . say , move the partitions as wanted until the free space comes after your desired partition .
example : /dev/sda3 is you desired partition ... and after dev/sda3 you need to have unallocated space.
2 . i am also new to this whole lvm thing . i am searching on it .
ok.found that . i'm citing from here
(which also has lots of other useful infos ) .
Before we can extend an existing volume group we need to create a physical volume:
# pvcreate /dev/sda1 (modify with YOUR partition )
Physical volume "/dev/sda1" successfully created
And now we extend the VG:
# vgextend maingroup /dev/sda1 (again , modify with YOUR paritition)
Volume group "maingroup" successfully extended
excuse me , but now that i see what you have , you can grow it easily , you do not haave to move partitions around