Welcome to beekeeping.
I have a few explanations on your findings. Beginners seem to find that bees flying around them seem to be agressive. That is false. Having 20 or 30 bees trying to sting you at once, is aggressive. Also, the hive that you have may have still had almost all of its population inside due to the recent rain. That is usually never good. I always inspect the hive when its between 12 in the afternoon till about 6 in the evening. Nobody likes being cooped inside your house for a week, especially if you know if you go outside you'll die. Anyways, did you use smoke? Did you have your veil on? If you have you veil on, don't go running and rushing through things. Take your time, and if you get stung a couple of times, simply close it up nice and smooth. One of my cousins wasn't wearing a veil and we went into the brood chamber. He got stung on the eyelid, and through the frame about 20 feet away from him. That WASN'T good. Anyways, if you have a new hive, I always give the hive extra time to work itself out into a routine of laying eggs and such.
Hope I gave you some good advice...