Hello, welcome to the community Big Dog. A 75 gallon tank is a really good size.
My suggestion is have some fun going to local fish stores, as many locally owned ones as you can to just take some notes on what fish keep catching your eye. Sometimes you might find a particular type of fish you really love, and build your community based from their specific water requirements. Some fish prefer hard water, or softer water, or cooler temp or warmer temps. It is best to keep fish together which require the same type of conditions.
Also do you know what type of water you have from your water provider? Ph, hardness, what types of minerals, etc. Your water provider may have a water report online. Or if you call them, they may be able to give you direction.
Another fun thing is to see if there is a local Aquarium Society which is near you? I just checked and there are several for your state. They usually have some meetings and speakers and people locally who keep and breed fish of all types. There are also Killifish clubs, Cichlid and Koi and pond clubs as well if you find you are drawn to a particular kind of fish.
So, when you know what you might like to keep, there are other thoughts to help decide on which fish, like some fish swim at the top of the tank, say Hatchet fish. Others, upper level, mid-level, lower and bottom, like Cory Catfish. And finding varied shapes of fish as well as colors and pattern can help create an interesting tank.
You also want to consider what type of cycling of the tank you want to try. Fish-in or fishless. If you have someone who has a healthy tank, they might be willing to share some media from their filter to help build a beneficial bacteria colony which gets the nitrification cycle going.