How do I play these chords on piano?

Q. Hi, I'm a beginner at playing the piano, and I've just written a song with the chord structure D2, C2, A1, A#1.

However, I dont know how to play these chords fully, they are just individual notes being played one at a time.

I want to know which 3 notes do I have to play simulatenously to make each chord. i.e. hold x note, ynote and z note to play D chord..and so on for the others.

and also if I just want to use 2 notes for each chord instead of 3, which notes would they be, for the same chord structure.

Many many many thanks.

Dan

A. I think your piece is in D minor.
The A# is actually a Bb.
(Same note either way)
If you want to play only two notes, I would skip the middle note, but either two notes is actually fine.

Dm - D, F,A
C - C, E, G
Am - A, C, E
Bb - Bb, D, F

I could be wrong, so experiment with it if needed.

Original Question

Can anyone help me figure out what song this is?

Q. The most I can tell you of its origin is that I most recently heard it in a Korean drama called Soul/Possession...
It plays in the sad/emotional parts.
Although I took the liberty of trying to figure out how to play it on the piano, and found a simple single note progression that matches the part of the song I remember.
it goes like this:
F A E A, D G D C#, D F D F, D F F E, and then plays again...thats all I can remember and there may or may not be other extra chords...anyways can anyone help me figure out what its called?

Original Question

Title : How do I play these chords on piano?
Description : Q. Hi, I'm a beginner at playing the piano, and I've just written a song with the chord structure D2, C2, A1, A#1. However, I dont ...