Don't worry, be ready. Uh, to add fish.
Set the tank up with water, declor, add the gravel or sand you want, get a filter or two and add a light and lid.
Get some filter squeezings as said above to cycle quickly. or feed a little food to the tank over a week or two to cycle without fish. Add one or two fish to help start if you just go the feeding route. Add more fish as time goes by.
Pool filter sand is basically prewashed, available from swimming pool supply places and looks good. Add some argonite or calcium carbonate rocks if you want the pH to be high, like for Rift Lake cichlids.
I recommend two filters on all large tanks. You can clean one while the other is still working.
I recommend two heaters. Two 100 watt heaters on a 75 gallon ought to be fine. If either fails off, the other should be good until you see what is going on. If one fails on, you also should have time to see the temperature rise and do something about it.
I do not like lids but lids do keep moisture out of your living space and help prevent jumpers.
A really nice light or two lights are in order to make the tank look great.
Always include bristle nose catfish in your selection of fish. They will keep the glass clean so you will not have to clean it except once in a while to get tough algae off. Probably 2 or 3 in a 75. But they need places to hide like rocks or driftwood. They clean at night mainly.
