Writing contests can receive hundreds of submissions. Thousands sometimes.
A lot of people write and a lot of people want to be seen or validated. Contests can be the easiest way to make that happen.
If you're submitting your writing to a contest, don't forget that you are one among many.
Of course, you have to make sure that you meet all the writing requirements. Word count. Formatting. Theme. Etc.
Above all that, however, remember that you have to stand out. The best way to do that is to be yourself in your writing. Show them who you are and who no one else is. Write what you are and what you know.
Stand out by being yourself. The right contest will come along and give you center stage when it's the right time for you.