Humor is so difficult because people can have many different opinions on what they find funny. Some have a dark sense of humor, some like puns, etc. so what one person might find completely hilarious, another might find insensitive, cheesy, or just plain not funny.
I would agree with The_Potato_Writer, as sometimes I write something and I think it’s funny or laugh at it, and therefore I hope some find it funny as well.
Something else might be to pay attention to what you find is funny, like when you read other stories or watch shows or movies. What makes you laugh or at least chuckle? What motifs do they use or what patterns do you see? (I am by no means encouraging copying, but at least gaining an inspiration or insight as to how others do something you want to achieve)
Maybe ask for feedback from a variety of other people (I know you’re not asking for feedback here, but maybe in another section like in the Read for Read section) and specifically ask folks what they found funny/if they found it funny and suggestions for improvement. This isn’t a foolproof way of improving, as you might run into people who aren’t helpful, but maybe more outside opnions might help.