They say you should show instead of tell.
I’m not as fond of the phrase. Words can’t show anything in the literal sense, they can only tell things. But the point is valid. We only want you to tell us interesting things. Let me try to illustrate the point.
I could tell you that Mrs. Bumble was an absent-minded and unfocused woman.
Or I could tell you that Mrs. Bumble once set out to bake a cake. She began by washing her hands thoroughly and walked away from the sink leaving the water running. She got out her recipe book and followed the instructions. First, she turned the oven on to the designated temperature. Then she got a bowl and measured out the flour into it. Leaving the flour on the counter she then took out the sugar to measure. Next came the butter out of the fridge. But when Mrs. Bumble went back to the fridge for eggs, she discovered to her mild annoyance that she’d had the last two for breakfast that morning. The market was only a fifteen-minute drive away so Mrs. Bumble, still in her apron, put on her hat and coat and shoes and went out the door. Only by the time she reached her car she realized she’d left her keys on the front table. So back she went, retrieved the keys, and drove to the market. The oven was still on and the tap was still running.
You see, I could tell you about Mrs. Bumble in a simple and short sentence. But it’s so much more interesting to tell you about something Mrs. Bumble does. If this were a full story instead of a blog post, I could go on and tell you about what Mrs. Bumble did at the market, how she interacted with the people she met, and what state she found the house in when she got back — if she ever got back. Knowing myself, I’d probably want to add more detail like what kind of house she lives in, why she was baking a cake, what the specific oven temperature was (researching different cake recipes if I was after realism), and whether or not Mr. Bumble is still alive.
The point, without that tiresome cliche everyone uses, is this: Don’t bother telling us about the character. Tell us about something the character does. It will certainly be more interesting, and it might possibly create your plot.
There might be a secondary point, which is that writing advice can sometimes be cliched and we need to make it more interesting for ourselves if we’re to benefit from its wisdom.