First you need to find your cervix! Use clean hands and insert one or two fingers. Your cervix is at the end of your vagina. Its kinda like a.....lump? Hard to describe. But thats it at the end. I've been checking mine for months and months and only just started to tell the difference between, hard, soft, open, closed, high, low, etc. There is a website called My Beautiful Cervix that has photographs of cervixes (is that a real word?)
As I have already had children, and cervical surgery, my cervix always feels a bit open, but I can tell the difference between "open" and "closed". It took a while.
I also have a retroverted uterus, but can still find my cervix. I have learned that when i'm fertile, my cervix is realy high and hard to reach, and right before AF is really low and feels really soft.
I check mine while sitting on the loo. Make sure you are in the same position each time you check.
Hope this helps. xx