wow! what a lot of bees to start off with!
One thing though; you say that you have put a second brood chamber and a super on today: do they completely take up all of the brood chamber in the picture yet or are there still some undrawn frames in there?
I ask because bees don't like it when you give them too much to do all at once and they might not draw out the new foundation in the second bc or in the super. Perhaps just put the super on if the weather turns nice again, although we are due for some serious rain over the next week so there won't be much foraging to do for them to start filling it.
The second bc will be very useful to allow you to change the comb over when there's not a honey flow on... June would be good to do this in and that way you can change them onto clean comb which will help to reduce disease and makes your job as a beekeeper easier because you will be able to see the eggs in the clean white cells, as opposed to old brown wax which is hard to see anything on!
You also may need to get a feeder to feed them sugar syrup - it's amazing how quickly that many bees could go through the honey in the stores and if the weather is as bad as they say it will be then all they will want to do is stay home and clean house!
I'm not the worlds best beekeeper but these are things that I learned the hard way last year when I first got mine. The other thing is, if you ask 3 beekeepers how to do things you'll get 5 different answers so see what works best for you and good luck!