The tank cycle will take a few weeks, so as said above, be patient. Your ammonia levels ideally should hit .4 before starting to climb down to zero. Then test nitrites and watch them fall. When ammonia and nitrites are at zero. Do a 50% water change over two days to bring down nitrates and your cycle is complete and ready for the CUC to go in. As far as temp goes, what kind of lighting are you running and for how long? If you cannot get it to drop, check your heater, it may need calibration. You can also add a small fan that blows across the water surface and this should cool the tank 3-5 degrees. (depending on the room temp) This is evaporative cooling so you will go through more top off water, just keep an eye on it.
Good luck and do not panic when the algae starts showing up very soon. It will most likely be a brown coating. These are diatoms and will go away as the tank stabilizes. You could also experience hair algae and cyano, so be careful about running your lights too long at this stage. Once the CUC (snails and crabs) go in, then you can work towards a full light cycle.