I have two questions about Master of the Mystic Arts. 1.Can I see the second card in Invocation deck during…

Yes and yes. Using Master of the Mystic Arts, you resolve the Special ability of the topmost Invocation card, which always places the card in the discard pile. At that point in time, you’d reveal the new top card of the Invocation deck. Then, you’d finish MotMA and place the resolved Invocation card back on top of the deck. If the deck emptied with the resolved card going to the discard pile, then the deck is first shuffled, and the resolved Invocation is placed on top of the new deck.