I'll leave the military aspects of Frank's life to the experts, but his marriage certificate will give his father's name, and his birth certificate will give both of his parent's names, so purchasing a certificate or two will enable you to trace his family.
There are a couple of births for Frank Ibbotson in 1918 - this one is in Bradford district:
Births Sep 1918
Ibbotson Frank
mmn Willis
Bradford 9b 137
(of course if his name was Frances, there may be other possibilities)
According to this his mother's surname is Willis.
There is a marriage seems to fit the above details:
Marriages Jun 1915
Ibbotson George
Willis Maggie
Bradford 9b 473
This is just speculation and you should really purchase Frank's marriage certificate to confirm his father is George. You can order here:
http://www.gro.gov.uk/gro/content/certificates/default.aspUsing these details:
Marriages
Jun quarter of 1943
Ibbotson Frank
Richards Dilys J
district: Liverpool S.
Volume: 8b
Page: 144
Let us know if you need further help with this.
Added: I have just checked the CWGC (which I should have done first), and see that the above details are correct and his parents are George and Margaret. You probably don't need to buy that certificate now.
But depending on where you wish to take your research, it might be worth purchasing the marriage certificate of George and Margaret, hoping it gives an age and occupation for George. There are a number of George Ibbotson's so we need more information to work out which George is the father of Frank.