Is the female genitalia supposed to have 2 openings besides the anus? Because I only have the very narrow opening which I assume to be the urethra.

Normal anatomy. Yes normal female anatomy includes urethra, vagina and anus. If you are able to urinate you have a functioning urethra. You may not have an opening to your vagina or in rare cases the vagina can be absent. Please see a board certified ob/gyn for an exam.
Yes. Yes, a female has another opening besides the urethra -- it's called the vagina and is between the urethra and anus. In some cases it can be very narrow or even absent. In some cultures there may even have been certain procedures done which close or obstruct the vagina. I don't know how old you are, but seeing your physician or ob-gyn would be a good idea. S/he can examine and advise you.