I have the Hawkeye 5 gallon tank from Walmart.
I am putting a 25 watt Hydor Theo that I ordered from Foster & Smith - this particular heater does turn itself off and on and you set what temp you want the water at. Some heaters don't.
I also snagged a thermometer to go in the tank as a double-check.
You'll have to add the bacteria in. I'm trying Dr Tom's per a suggestion on another post on this board (found it at Foster & Smith too and due to temperatures along my shipping route I ordered it from F&S thinking the happy bacteria should survive the trip - extreme heat/cold can kill it).
**Edited to say you don't HAVE to add the bacteria in - but for tanks I've done in the past I prefer to. I think if you get a good bacteria starter it just helps jump-start your tank cycle and makes life easier on your fish since the good bacteria is in there to start breaking down the fish waste. Still have to monitor closely though and be ready for extra water changes in the beginning if need be. I plan to put the bacteria starter in the day I put the fish in.
Water conditioners are liquids you put in the water to remove/treat the chlorine and other chemicals in your water, so they don't kill your fish.
Not sure what you mean by a machine - unless you've come across reactors, skimmers, UV sterilizers and all that fun stuff while researching tank supplies. Those are other things entirely