What's the difference between on how to pronounce things that are feminine or masculine?
I don't know how to tell if something is masculine or feminine.
I'm not sure what you mean.
If you're talking about the definite article, male "le" is pronounced like "luh". Female "la" is pronounced with a more open vowel sound, like "lah".
For "un" and "une", the male "un" is like saying "ahn" but nasalized, so you don't fully pronounced the "n". The female "une" is like saying "oon" and you DO pronounce the "n" since there's an "e" on the end, and the "oo" sound is more like the "u" is the word "tutu".
As far as actually being able to pronounce these sounds, listen closely to the sound records and practice trying to mimic the sound. It may take a while but if you practice enough you'll get it.
At the beginning of the sentence It will sometimes say 'La' or 'Le'. La signals feminine and Le signals masculine. If you know which gender the subject is because of la or le, then you can also figure out what the gender for the rest of the stuff should be. I'll give and explain of both sentences. Feminine: La chienne mange une pomme. Masculine: Le chien mange une pomme.
You can't always tell from the pronunciation of the 'thing' itself. The article gives away the gender.
In French, a lot of masculine and feminine words have different endings, but some have similar endings and same pronunciation. Of course, there are those words where the exact sound of the word may give away the answer.
However, the only thing you can depend on is called an article. It's 'a' or 'the'; in French, 'un', 'une', 'le', 'la', and 'les'. You can count 'du', 'de la', and 'des', too. Did you notice how there were many more articles? That's because there's one for each of the three cases.
By cases, I mean one of these - masculine, feminine, or plural.
The masculine the is 'le', which you will hear a lot. The masculine a is 'un', and, without an e at the end, its pronunciation is different and so the article can tell you the gender.
The feminine the is 'la', which you will also hear a lot. The feminine a is 'une', which sounds different from 'un' (listen to stuff at forvo). The pronunciation of 'une' can tell you if the 'thing' is masculine or feminine.
The plural the is 'les' (note that there is no equivalent in English as we say 'the dogs'). Although the plural form of the 'thing' may be able to tell you if something is plural already and the 's' is usually silent, it will help with enchainment and vowel starting words. There is no plural 'a' since a is always singular.
The extra 'du', 'de la', and 'des' are for 'some'. 'Du' stands in replacement of 'de le', and is the male 'some' (du gateau). 'De la' has no replacement and is the female 'some' (de la limonade). 'Des' is a 'plural some', regardless of gender (des biscuits) - note that even though the 's' is silent 'de' is not used as an article, so there is no confusion.
Correct anything that is wrong.
Hope this helped!