OK. Simulators.
As @gunja99 says, as a rule, you need a proper transmitter that supports USB connection to use as a controller, although some support gamepads (passable), keyboard (almost impossible) or touch screen controls on mobile devices (very difficult).
While we are usually talking about FPV/racing simulators, it is worth noting that there is also a DJI Flight Simulator on PC which is compatible with your DJI controller.
Of the rest, a few have already been mentioned, but here are the main ones I know about.
ORQA FPV.SkyDive
FREE on Steam (although there is an additional map available for £2.09)
There is also a free beta version available on Android
Flowstate
FREE on Steam
Edit: Just tried this (hey, it’s free) and could not get it to see my controller. Uninstalled
FPV Air 2
£3.99 on Steam
FPV Freerider
£4.79 on Steam
There is also a free demo version on their website and on Android
Drone Racing League (DRL) Simulator
£7.19 on Steam
Uncrashed
£10.99 on Steam
Liftoff
£16.99 on Steam
Velocidrone
£16.99 from their website
AI Drone Simulator
£19.99 on Steam
This is by no means an exhaustive list and others are available on various platforms.
Key points to note are
- If you’re new to FPV, it’s a very steep learning curve. I first tried on an Android sim and assumed it was broken. It took me about 8 hours before I felt even slightly in control.
- Of the half-dozen or so I have tried, they are all pretty much of a muchness until your skills get to the level where you can spot the differences. Everyone has their favourites.
And, of course, here’s Mr. Bardwell to tell you about them all (well, quite a lot of them). 
@bannerman100, if you want to give FPV a go for zero outlay then, by all means, have a look at the free demo FPV Freerider on Android. This isn’t the mobile simulator I first tried (I can’t remember what was) but I can tell you that even now, after 50+ hours of FPV flying, I had a job getting to grips with the touch-screen controls. It’s do-able, just, but it does make something that is already really quite hard just a little bit harder. 
Alternatively, you might well be able to find someone who’ll be willing to give you a taster and get you started down the slippery FPV slope. Maybe at The Big Meet V2?