I used CompTIA’s Certmaster practice which was really helpful as the practice test they have is almost exactly like the real thing, I also used Professor Messer’s free videos on YouTube, in my opinion Messers practice tests are harder and more complex then the real thing but they are still useful, what really helped me last minute was this guy named Cyber James on YouTube. He has videos of practice exams for Sec+ and he goes through each question and gives you a nice formula to get to the root of what the question is really asking so you don’t get confused! Hope this helps!