Learn Italian: Marco ha due macchine.

No. Unlike the number one (uno or una), the number due (two) never changes its form. Numbers from two upwards stay exactly the same whether they are describing masculine or feminine nouns.

Is the h in ha pronounced?

No, the letter h at the beginning of a word is always silent in Italian. You pronounce ha exactly like the vowel a. It is the he/she/it form of the verb avere (to have).

Why does macchina change to macchine here?

macchina (car) is a singular feminine noun. In Italian, feminine nouns ending in -a change their ending to -e in the plural. Because Marco has two of them, we must use the plural form macchine.

How do you pronounce the cch in macchine?

In Italian, ch makes a hard k sound. The double cc means you hold that sound slightly longer. It is pronounced roughly like MAHK-kee-neh.