Is there a good quad sim out there that I can practice racing and/or freestyle without trashing my rl quad?
Yup! There are several!
Velocidrone,
http://www.velocidrone.com/ works as an FPV simulator on both Mac and PC. Not one of my favorites, but there are a lot of people I know that like it.
Rotor Rush -
http://rotorrush.com/ - Also for Mac and PC, allows you to simulate flight on the TinyWhoop/Inductrix style frames. I haven't flown this one myself, but I've seen some reviews that say it's pretty good.
DRL Sim -
https://thedroneracingleague.com/2019-tryouts/ This one works for the Drone Racing League, and is used as something of a qualifying tool to see how you'd place for their courses. It also runs across Mac & PC, but I couldn't get it to run well on my Mac Mini from 2016, so I kind of gave up trying to use it. You may find it runs better for you with your setup, depending on what you have.
Liftoff - h
ttp://www.liftoff-game.com/ - This is my favorite. I'm not a huge racer; I like to fly more freestyle flight. This one gave me the option to do so with tons of different courses to run through, as well as the option to build my own courses. This one also has a Betaflight tuner in the game, and tuning corresponds fairly well with real-time tuning. I actually used the settings in game to get a really close approximation of real world tuning for my quad.
Of these 4, I know for sure that Liftoff, DRL Sim, and Velocidrone will all work with Spektrum and the OrangeRX USB wireless dongle; I have tested those and gotten them to work. Rotor Rush says it will work as well, but I myself have not verified that; your mileage may vary.
Everyone has different feelings about the simulators; some say that it doesn't feel like real life, that they're too "floaty". I spent 40 hours (spread out over several weeks) in Liftoff, learning how to fly a quadcopter in Acro mode on a transmitter. I then got a racing quad for my birthday, purchased an inexpensive box headset, and went flying a week later. Pulled it out, flew it around, and was doing loops and rolls with it, no problem, just like I did in Liftoff, and everyone who watched me was amazed, considering I'd never flown in real life before. Practice with a transmitter (don't try to use a USB gamepad like a Playstation or Xbox controller; it will NOT give you the same feel!) and you'll benefit from it. It's not quite the same as real flight, but let me tell you that you WILL benefit from the practice and getting muscle memory set.