Hi and welcome!
I'll start off by saying that axolotls are very different to fish - I did so much research before I got my tank, and my partner and I set up a cichlid tank and a guppy tank at the same time. All tanks were cycled before we got any animals, and the cichlid tank has had no dramas. Everybody is happy and full and nobody argues. The guppies don't care about anything. My axolotl tank is currently at 29 degrees with one lonely little guppy occupying the space. One of my axolotls has died and the other one is not happy.
I'm sure you know all about ammonia and nitrite and such, but it's especially important with axolotls - it's really toxic, even more so in higher temperatures. You should be fine with your water changes, but I think it is recommended to do partial water changes daily until the tank is cycled - just keep an eye on the water parameters and make sure ammonia and nitrite stay at 0. If you find you're getting readings for them, maybe up your changes to once a day.
Here is some literature for you to bury your nose into
As geosheets said,
www.axolotl.org has lots of basic information on everything axolotl.
Info on cycling, though you probably already know all this stuff if you keep fish -
http://www.caudata.org/cc/articles/cyclingEDK.shtml
The axolotl care page -
http://www.caudata.org/cc/species/Ambystoma/A_mexicanum.shtml
As for food, beef heart is ok as an occasional treat but axolotls don't digest it well so it's not great as a staple. Earthworms are the best if you have access to a pesticide-free garden or a bait shop. If your new friend is still small, you may have to chop the worms into smaller pieces so he can manage them. Bloodworms (live or frozen) are good too, although they are messy and require some skill to feed neatly. The only live food I can find in Brisbane are earthworms and baby guppies that I'm breeding. Axolotl pellets are also good if you can get him to eat them. My little guy stopped eating for a while, and I made a concoction suggested by Darkmaverick and it's been happily snapped up (although I make a massive mess with it)
Darkmaverick said:
I personally feed sick axolotls a 'miracle mash'. What i do is to use a food processor and blend the following (or a combination) - fresh shrimp, bits of fish fillet (avoid white fish), beef heart, even earthworms, and moistened axolotl pellets. I would then roll this dough into pea-sized portions before offering. I find that the mash is commonly accepted by axolotls because firstly, it is easily ingested (small enough) and digested, has nutrition due to the composition of the mash, is easily prepared and stored in the fridge, and its generally quite palatable due to the smells associated with the ingredients.
You can buy a marinara mix from the supermarket that has lots of goodness in it - I blended that with pellets and beef heart, although I did remove a bit of the white fish from the mix. Mine won't eat unless I wave it right in front of his nose - feeding tongs from the pet store are good for this.
Here are other food ideas
Food ideas -
http://www.caudata.org/cc/articles/foods.shtml
Another thing to note is that pet stores tend to be misinformed when it comes to axolotls. Check out the housing page on
www.axolotl.org and make sure everything is good. They will usually recommend gravel, which Max will eat - this could lead to impaction (which can lead to death). A barebottom tank or clean sand are the best substrates. They will also become stressed by stupid little things - water flow, temperature, light, tank mates. You probably already know to pick up their waste and uneaten food every day - A turkey baster makes this a lot easier. It's important to make sure you don't let waste accumulate, especially when it's hotter and your tank isn't cycled.
Now for cooling.
Here's a page on different cooling methods.
http://www.caudata.org/cc/articles/cooling.shtml
A chiller is obviously the best method, but it's also the most costly. You can try rotating water bottles - make sure you read the instructions on that page and do it properly though, as fluctuating temperatures can be even worse than having the tank hot. This works for most people, but I find I'm never there to change them on time and I don't have enough room in my freezer for a million bottles. To make this method work even better, you can insulate the outside of your tank with styrofoam or something (get a hold of one of those boxes they use to transport fish to fish shops and cut the sides out to wrap around your tank). This makes the frozen bottle method more effective.
Fans blowing across the surface can also make a significant difference as well I think.
However, I've given up. I invested in a chiller and am still trying to make it work. As an emergency measure, Jacq suggested I use an esky and Kaysie helped me figure out how to make it work.
I've got an esky half full of dechlorinated water (I just like to dechlorinate everything). In the esky, I've got a large container full of water, and a smaller container full of water floating inside the larger one. The axie lives in this smaller container. The bigger container helps to buffer the temperature change, keeping it gradual.
I originally had ice in there (no room in the freezer for ice bottles at xmas) but now I rotate frozen bottles. You need 2 bottles - one in the esky and one in the freezer. Once a day I swap them, using the old bottled water to change 100% of the axie water (because it was in the esky with him, it's the same temperature). Using a 1L bottle, the temp in his container drops down to around 14 degrees and it takes 24 hours to creep up to around 18 degrees. I also keep a bottle in the fridge and put that one in the esky with the frozen bottle - if they're both frozen the water gets too cold, and I need another bottle to fill his container. If it's getting warmer and I'm going out, I'll swap one of the bottles with another frigded bottle, just in case. This doesn't drop the temperature, it just keeps it cold.
This method doesn't allow you to watch your axie play, and kind of sucks. But it's keeping him happy and healthy until I figure out a more permanent solution, or until the weather cools down. If he were in the tank he wouldn't be playing anyway, he would be boiled to death. Try using the search function of these forums to find other posts on cooling and heat stress - there will be millions.
Sorry about the essay, but I hope that was helpful! Good luck, Aussie summers aren't kind to axolotls but once you've got it all sorted out they're so adorable to watch.