Learn Arabic (Modern Standard): هم مع المدير الآن.

هم is the masculine plural pronoun for "they." In Arabic, you use this for a group of all men, or a mixed group of men and women. If the group is entirely female, you must use a different pronoun, هن (hunna).

Where is the word for "are" in this sentence?

Arabic does not use words for "am," "is," or "are" in the present tense. You simply put the subject هم (they) right next to the information about them, مع المدير (with the manager). The "are" is naturally understood.

Could I attach هم to the word مع?

Not in this context! Here, هم is an independent subject pronoun meaning "they" at the start of the sentence. If you attached it to مع to make معهم (ma'ahum), it would change the meaning to the object "with them" instead of "they are with".

What is the wavy line over the Alif in الآن (al-'aan)?

That symbol is called a madda. It tells you to pronounce the letter as a long "aa" sound with a slight catch in your throat (a glottal stop) right before it. So الآن (meaning "now") is pronounced "al-aan".