Learn Arabic (Modern Standard): هل التذكرة للقطار؟

This is a special spelling rule for the attached preposition لـ (li-, meaning 'for'). The word for 'the train' is القطار (al-qitaar). When you attach لـ to a word starting with ال (al-), the ا (alif) is completely dropped in writing. So, لـ + القطار becomes للقطار.

How do I pronounce the beginning of للقطار? Do I still say the 'a' from 'al-'?

No, you skip the 'a' sound completely. Because the alif is dropped in the spelling, it is also dropped in pronunciation. You pronounce it as 'lil-qitaar' (li + l + qitaar).

Why isn't there a word for 'is' in this Arabic sentence?

Arabic doesn't use a word for 'is' or 'are' in the present tense. You just put the subject (التذكرة, the ticket) directly next to the descriptive part (للقطار, for the train). The 'is' is simply implied by putting the two parts together in what is called a nominal sentence.

What vowel ending (tashkeel) would go on the last letter of للقطار?

It would take a kasrah (a short 'i' sound) under the letter ر (raa). This is because لـ is a preposition, and prepositions force the noun that follows them into the genitive case, which is usually marked by a kasrah at this level.