OK, first off, get an app or similar. Some people do do it on paper but that's a massive faff.
This is very bare bones:
Buy a thermometer that reads to two decimal places and use throughout cycle before getting out of bed. Your temperature spikes immediately after ovulation, so you do really need to know your cycle to time everything correctly.
You track your cervical mucus, before ovulation is the consistency of egg white.
Some women check their cervix every day to check positioning and whether it's hard or soft.
Obviously this is not what every woman wants or feels comfortable to do.
I liked it because it really made me feel in tune with my body and I felt very empowered by it. I learned that I do not ovulate on day 14, which is what I was always taught, it's more day 17 with me. PCOS can of course affect this too, which would save you buying ovulation sticks at the wrong time of the cycle.
Like I say, it's not for everyone. I think I used fertility friends website (this was pre apps really) and that was excellent.
That's a very basic run through. I wish you all the best!