I started out using those kits too, and I have some advice for you.
1. If you can, replace the corn sugar with dry malt extract. It will add more flavour and body to your beer.
2. Keep the fermentation temperature as steady as you can around 18ºC. There will be less off flavours in your beer.
3. If your fermentation bucket has a hole for an air lock, keep it sealed, and ferment for 3 weeks. Ignore the instructions.
4. When you bottle, keep the temperature at around 20-22ºC for 3 weeks. Your beer will be better carbonated, and by this time it will be 6 weeks old, and it'll taste better.
Now...why was your wort so warm? Did you boil it? If so, there's really no reason to do that. Just empty the contents into your bucket, fill the can with hot water and dump it into the fermenter. Do this twice, then top up with cold water. No need to boil the water first.
Bottom line: the instructions that come with those kits aren't going to yield the best results.