Finally I my Latin classes at school are helpful for something :D even though most is lost I remember "mulier, mulieres" ^^ Any other person thinking of that?:) The singular sounds pretty much the same
It's like lha=lya, lho=lyo and so on. Put your tongue where you eould if you were to make the 'l' sound and then make the 'ya' sound while moving your tongue to the bottom of your mouth. It's really tough to pronounce like native speakers, it took me like 6 months to get it down haha I hope this helped!
Nope, "um" is used in masculine words and "uma" in feminine words:
[Feminine] Uma casa (A house) Uma mulher (A woman)
[Masculine] Um carro (A car) Um homem (A man)
Hope I helped :)