New Jerusalem measures 12,000 stadia in height, width, and length. My house measures 1300 square feet. Can you show me the example of how many times my house will fit into the City of New Jerusalem?

There's a problem with your question. The dimensions you note for New Jerusalem are three dimensional, but the dimensions you mention for your house are only two dimensional. In order to give you an answer, I will make the simplifying assumption that you are only looking for an answer in two dimensions. In that case, here's how the math would work:

1 stadia = 607 ft 12,000 stadia = 7,284,000 ft a square which was 7,284,000 ft in length and width would be 53,056,656,000,000 sq.ft. (i.e., 7,284,000 x 7,284,000)

Thus, your 1,300 sq.ft. house would fit into that space 40,812,812,307.69 times (i.e., 53,056,656,000,000 / 1300)