You don't need to learn all the synth sounds that would take forever. You just need to get a grasp at recognising fundamental sounds... for example if you wanted to make a nice pluck sound you might want a sine wave with a low pass filter on it being controlled by an envelope with a short decay/sustain and some nice reverb/delay on it(that could be a starting point) Then from there you could decide if you want it to have a bell like character, which in massive you could experiment with the frequency shifter effect as it creates nice inharmonic overtones, once its tuned correctly. A good way to make sounds more natural though is reverb because it puts the sound in a real space, just don't over do it. Heres a video of the pluck im on about
https://www.youtube.com/watch?v=Ea4hw8rC9_Y