Everybody starts off as a hobbyist.
Softbox is just one type of light modifier or diffuser. Just remember this, the larger the "reflector" the softer the light. For example people know of bouncing a speedlite or on camera flash against a wall or ceiling but if the surface is not white you have a colour cast in photo.Also bounce flash does not offer much control of light output or shaping. That said the earliest light modifier is the cheap umbrella. You can get good results if you know how to use them, shoot through or reflected light. Next comes the other smaller light modifiers like beauty dish, and other lights for background and hair or rim light. Then there are directional modifers like grids and snoots. This all may sound overwhelming to you now but after awhile you become a pro..haha. The question now is with just one light source (ad200) can you have good results and yes if thats all you have now. Good luck. Oh forgot to mention you will need ad200 mount adapter for softbox or beauty dish. Most probably to a bowen's mount or godox type. Important...for best results your flash is best OFF camera meaning you will have to use a wireless trigger or commander like godox Xpro of course you can use built in on camera flash as a master trigger with ad200 switched to slave mode but it has it's limitation as the ad200 sensor has to detect the light from the camera. The ad200 has a built in flash trigger reciever so you just buy the xpro commander. This also lets the xpro commander to set settings from it instead of going to the flash which save you time.
Shooting with just one light.
Umbrella vs softbox