Would a complete blood count find glandular fever ?

No: Glandular fever (or Epstein-Barr Virus) is an infection caused by a virus. There are specific test that can detect antibodies to the infection. This is the best test. While a complete blood count (CBC) may show some changes consistent with glandular fever it is not specific. Lots of monocytes on a CBC suggests glandular fever (also called mononucleosis). I suggest you get an antibody test.

Not necessarily: It's possible to have a totally normal blood count, even differential - as in the breakdown of the different types of white blood cells like neutrophils, lymphocytes etc, and have a "glandular" fever. Sometimes you can see an elevated white blood cell count or increased lymphocytes, neutrophils or even atypical lymphocytes, depending on whats causing(often felt to be EBV-mononucleosis related).