Question

Where is the preposition in the sentence order?Is preposition has at the end of the sentence?or where?

Answer 1

There is no one particular place in any sentence for a preposition. The reason is that a preposition and the words that go with it (the prepositional phrase) are used to modify or describe different other words, and it's best if the entire prepositional phrase is placed as close to whatever it's modifying as possible.

In the morning, we are going to the theme park.
There are 2 prepositions and prepositional phrases in that sentence. Both of those are being used as adverbs, telling more about the verb:
"In the morning" tells when and "to the theme park" is telling where.

Here are some further explanations about prepositions and prepositional phrases:

http://esl.fis.edu/grammar/rules/prep.htm

http://www.eslcafe.com/grammar.html
Scroll down and go through the whole section on prepositions.

http://www.englishclub.com/grammar/index.htm