Ovulation tests

I know I probably sound stupid but can someone please explain to me how to use ovulation tests?! At what time of the month do I use them? When the glow app starts estimating my ovulation or? At what time of the day or multiple times a day? How do I know I’m ovulating? And when should I have sex based on knowing when I ovulate? As soon as I know I’m ovulating, before,after?? Any advice helps. I had no problems with my first pregnancy two years ago and then we started trying again and had a miscarriage in December. So I just want to try to track my ovulation to give a better chance of me getting pregnant sooner now.