Hi! I'm TTC #1 now. Good times, but oh so stressful at times! Checking your cervix is part of the whole puzzle. It can take a bit of practice to figure out what you're feeling for and then figuring out what it all means.
I'll try to help, though it's kind of hard to explain. So first, you should choose a position and use the same position every time you check. I check while sitting on the toilet. You can put your leg up on the side of the shower too.
Make sure to wash your hands BEFORE you check. You definitely don't want any bacteria up there. Then, insert your pointer or middle finger. You should insert it all the way and direct it kind of upwards. The inside of your vagina is soft and kind of bumpy. The cervix (when you're not close to ovulating) feels like a hard bump. Some people say it feels like the tip of your nose. There is an opening in it kind of like a dimple. Sometimes, when I feel it I have to move underneath what I feel to feel the dimple.
When you're not fertile the cervix is firm or hard (feels like the tip of your nose), low in your vagina and the dimple feels "closed." As ovulation approaches, the cervix softens, moves up (harder to feel) and the dimple "opens."
It really takes practice. You can check everyday and start recording what you feel. Once you get better at it, this will help you tell when you are getting closer to ovulating.
Oh, and the cervix can change during the day. It is best to check around the same time everyday.
I hope this helps. Good luck!