KK hand
Preflop
I like 4-betting, but your sizing is very large. The problem with that is, if you are going to fold to a 5-bet jam, you just lost 1/3 of your stack, and that makes it very unattractive to work in 4-bet bluffs. This dont really matter in a freeroll, because you should only be 4-betting for value, but if you eventually move up and play against better opponents, then you want to 4-bet smaller with 100BB stacks. Which by the way is super relevant for cash games.
Flop
The SPR is less than 1, and you just cant fold to this donk bet. Yes he could have QQ or TT and just flopped a set, but he could also just be running a stop and go with AK or a flushdraw or whatever. The hand is just a set-up, because its also difficult for him to get away from QQ in a freeroll, especially if he dont know you.
AA hand
Preflop
Standard 3-bet and perfect sizing.
Flop
Once again the SPR is less than 1, and even though its a connected board against multible opponents, you just cannot fold AA here. I also dont think, there is any value in letting cards roll off, so I would just jam, and then come, what may. I dont think, the board is quite as bad, as it might look, because in a 3-bet pot they really should not have KTo or QJo. So the hands, that really binked, are only KTs and QJs, which is only 6 combos. Yes they can have all the sets as well, but they can also have TT, which is 6 combos, and AQ, which is another 6 combos, or AK which is 8 combos and might call because "LOL gutshot and overs". And you need less than 30% equity to make a profitable stack-off. So it just is, what it is, and this time you were in fact ahead but got drawn out on. Good for them, time to register for the next SnG.