Depends on how far you want to go with it. FSOne offers a moderate variety of aircraft, and some flying fields. RF has a much greater variety, and thousands more with the user created ones.
FSOne if free, so little risk to try it out for a while.
You'll note that most advanced instruction (3D, etc.) on YouTube uses recordings from Real Flight to aid in showing how things are done.
Either will get you familiar with basic flight and greatly aid in developing the critical eye-hand coordination, given the constraints of simulators. RealFlight offers a much wider range of options and things to do, so may serve to keep you using it longer or in more depth. But then FSOne is free....
Things learned in FSOne will easily transfer to RealFlight later.
RealFlight is capable of VR if you have a headset, although not at a high level of quality. That combo can give you close to 100% the "at the filed" experience...even with its lower graphics in that mode.
I've used RealFlight since it first came out, have been flying for 55 years, and still use it frequently to work on skills or fly when the weather is bad.
I've made copies of my real models, which behave in the Sim just like the original - bad behavior and all. Then used it's Aircraft Editor to figure out what adjustments need to be made to make them fly better. So one can go deeper with that program, if inclined.
But if you're at all hesitant, FSOne, even with it's reduced feature set, is worthwhile to work with.