Is 1320 SAT (660 in R&W and 660 in math) good enough to get into colleges like UCLA, Georgia Tech, or University of Michigan? Interested in going into comp sci major
No.
Nope, retake it if you want a real chance at those. Study study study and you’ll get there 
Not for CS, no. Depending on where you live, you will have up to three chances in the fall, plus one in December. I would sign up now, though, as seats aren’t available everywhere.
Your score is probably fine for CS programs at some directional colleges. Make sure you apply to a couple of likely schools.
Average SAT for UCLA CS admits are in the 1500 range. Are you a CA resident?
You can look up the average standardized test scores for any college by either: 1) googling the class profile; 2) googling the common data set for the college or 3) looking at recent college guide books. Understand that CS is one of the most competitive majors so the scores may need to be above average.
But keep in mind that some colleges are going test optional for next year only due to covid situation. Again, you can do a search to find out if the specific colleges you are interested in will require standardized tests or not.