A Wg Cdr at a careers office? Doesn't sound right. Never saw anyone higher than F/L there and only ever saw Wg Cdr during reviews at OASC, post-tests.
Anyway, if you join clubs after uni you'll be asked why you didn't join any during uni, you'll be asked why you didn't join the UAS and any other societies going and unless you get a very high First they won't really buy the 'concentrating on my studies' line - consider that unfair if you wish.
Fact is you'll be up against hundreds of applicants who also have degrees but masses of extra curricular activities, be it Football, Rugby, Hockey, Skiing, Harry Potter Society or Tiddlywinks... what do you have to make yourself stand out against them?
They will also ask you, unfairly or otherwise, if you thought you were managing your time effectively if you had no time available for any of these activities.
Like it or not, the RAF/Armed Forces in general want rounded individuals with many and varied experiences. If you can't offer them that, they'll go elsewhere.
Many will also tell you the PPL was useless for an RAF application, so be aware of that.