Learn Farsi: یک بشقاب و یک لیوان.

It can mean both! In Farsi, placing the number yek (one) before a noun is a very common way to say "a" or "an". So yek boshqāb literally translates to "one plate", but it is the standard everyday way to say "a plate".

Is the word for "and" (va) pronounced exactly as it is written here?

In formal reading, yes, it's pronounced va. However, in everyday conversational Farsi, the word و is almost always shortened to just an "o" sound that links the two words together. A native speaker would say yek boshqāb-o yek livān.

If I want to say "a plate and a glass", do I have to repeat yek for both words?

Yes, it is most natural to repeat it. You put yek before each noun to show that each individual item is indefinite, just like you would normally say "a plate and a glass" rather than "a plate and glass" in English.

Is there another way to make a word indefinite besides adding yek?

Yes! You might remember that Farsi also has an indefinite suffix -i that attaches to the end of a noun, like boshqābi (a plate). Using yek before the noun is just another very common method. Sometimes, native speakers even use both together for extra emphasis, like yek boshqābi.