I have noticed that a lot of us that take the risk to make and create things suffer from what I call 'tortured artist syndrome". An example of this syndrome, is the questions that used to go on in my mind when I was creating (and I must admit still sneak in occasionally)
What colours should I choose?
Whatever made me think I am a painter?
No one else will like it. etc, etc
Now, I have come to the realisation nothing matters except for the fact that YOU like what you have created. We all have different styles, colour preferences and tastes.
It is art and the beauty is in the eyes of the creator. That is all that matters.
You do not need to be an artist at all! Just paint away until you like the look, and be prepared sometimes you may have to leave it for a while and think about what direction you are going in. Sometimes you may completely start again! It is all part of the therapeutic process that is Chalk painting and creativity.
Stay safe and paint yourself happy in the meantime!