Learn French: Il y a quelques fraises dans la confiture. - There are a few strawberries in the jam.

The phrase un peu de means "a little bit of" and is used for uncountable things (like water, sugar, or jam). Because you can count individual strawberries, French uses quelques, meaning "a few", instead.

I thought il y a means "there is". Why is it used for "there are" here?

In French, il y a works for both "there is" and "there are". Unlike English, the phrase doesn't change when you are talking about multiple things like the strawberries here.

Do I need to pronounce the "s" at the end of quelques and fraises?

No, the plural "s" at the end of both quelques and fraises is silent. You pronounce them exactly like their singular forms.

Why does the sentence use la before confiture?

The word confiture is a feminine noun, so it must be paired with the feminine word for "the", which is la.