I’m thinking of not taking the essay as I want to focus as much as possible on the score. Is this a wise decision? If not, can I retake the SAT in December and take the essay? Will my final SAT score be affected if I get a lower one in my second try?
So many issues in one question!
You can take the SAT either with or without the essay.
However, unless you now FOR SURE that none of the colleges you are planning to apply to need the essay…it is best to write at least one SAT with the essay.
You can retake the SAT whenever you want…as long as it is in time to be considered by the admissions department.
Your “final” SAT score can be the score you get in November…or it can be the score you get in December…or it can be a “superscore” of the highest English grade and the highest Math grade…it all depends on the policies of the colleges you apply to.
SO - my suggestion - look at your college list. Research the SAT essay requirements for all those colleges. Then research whether or not they want only your highest SAT scores, or they want to see all your SAT scores or they superscore your SAT.
When you have done that work - you should have your answers.