From Visualization of Heap Operations:

A heap is a specialized tree-based data structure that follows specific rules for organizing data. It comes in two main types:

• Max Heap: Each node's value is greater than or equal to its child nodes, making the root node always the largest value in the heap
• Min Heap: Each node's value is less than or equal to its child nodes, making the root node always the smallest value in the heap

And back to your question

1. Yes. A sorted array is a min heap.
2. When you use a max-heap, you should focus on the maximum value, which is the top of the tree.

By the way, you can visually understand the concept of heaps at the previous site.