Vectors are equal if they have the same?

In many cases, not all, a number is defined as the length of a line. Then we need to distinguish between positive and negative numbers, so we say a positive line goes to the right and a negative line goes to the left. So there you have the basic vectors: a number and a direction. But the direction can be any direction, so trigonometry gets involved to combine vectors.

But that is beyond your question. Vectors are equal if they have the same number and the same direction.