As a pianist or guitarist, you should be able to locate any chord on your musical instrument easily, be it major chords, minor chords, diminished chords or augmented chords.
When you can do that very well, then you can now take up the challenge of applying the chords to accompany various songs. It’s a gradual process. The more you practice the more you know.
Every song has its own chord progression. However some songs carry the same chord progression with each other. Sometimes they carry the same chord but different timing.
So before you think about accompanying and song. Determine the chord progression and the timing. Those two factors are very important.
The main reason why people don’t enjoy your play as a beginner is because you don’t play the correct progression and because your timing is wrong.
Make your play as simple as possible. You don’t need all the complex chords and passing chords in this world to sound cool. Be simple and neat. Most hit songs that we know are built on simple theories.