Check on the website which ones actually offer engineering, as a few 'campus' choices (or Colleges) don't offer certain subjects like Vet Science, or like you Engineering.
The campus choices vary in atmosphere and age (its a little late to visit them now and sample it, but will try and help!).
Some colleges (campuses) are only postgrad: Lucy Cavendish, Wolfson, St Edmunds, Clare Hall and Hughes Hall so not these if you're in sixth form/college atm.
Newnham, Murray Edwards and Lucy Cavendish are single-sex (female only)
Some of the colleges are more modern in outlook and architecture; these include Robinson, Fitzwilliam, Churchill, Murray Edwards, Girton is late Victorian.
The older ones such as Emmanuel, Trinity, Peterhouse, Jesus, Clare, Magdalene etc. are all percieved to be harder to get into and seen as arguably more prestigious by some, so I would not advise applying to these if you are unaware of the college system.
St Johns is mega-posh apparently.
Fizwilliam has been generally the pioneer in attracting more state school students to Cambridge.
Or you can make an open application which basically just allocates you to a campus or college, you may prefer this option seeing as its a bit late to start making detailed investigations now!
Good luck anyway, hope this post helps.