A Bug's Life

indeed, I don't know how the manufacturers chose to label the gears (because my bike just assumes you know) but generally, you should try and keep the effort the same - use the rear gears (1-7) first and if you move in the wrong direction, you'll find you are working harder so go the other way (honestly, that's how I figured it out, and it becomes automatic quite quickly). When you change front gear, you may well need to change the rear gear in the opposite direction to compensate. In Cambridge, you might well find it easiest to stick to the middle front gear (2 of 1-3) and just change up and down the rear gears (1-7), except on the really steep bits (where steep means Castle Hill in places, the Gogs and maybe the cycle bridges as far as my bike is concerned but of course YMMV)

Your brakes will be very lively since they are new, at the speeds you are likely to be moving you can probably get away with just the rear (probably right hand but check) but if you need to brake sharpish, do use both hands, and in either case be gentle.

One thing we forgot to say in among all the other rules, never* cross your gears - i.e. don't use the large front gear with the large rear one, or the small front gear with the small rear one (you'll have to translate this into the numbers on your gear changers) - the middle front gear can probably be used with all the rear gears but would prefer not to be used with the largest and smallest.

*for values of never meaning it won't kill you, and you might well get away with it, but it's bad for the equipment and may lead to your chain coming off