Bbt help please

I’m want to start tracking bbt but I have no idea what I’m doing I know to get a certain thermometer and to temp before getting out of bed in the morning what else is there more to it or is that it and how do you know if you ovulated I’m so confused please any help is so appreciated and thank you in advance

Thank you Ana 🫶🏻 and is this a good one?

Ok thank you Sandra