Over

It' a direction. You might see "over there" to name a place.

In your sentence, the word "over" is not needed.

"Over" used this way is conversational, or as the British say, "chatty", and definitely informal. It is normally used to refer to a (literal) place away from "here".

It is normally used to refer to a (literal) place away from "here".

Would you please give me some examples ?

Thanks again for your kind help.

I am here; you are over there.
I am in London; my wife is over in Paris.
I walked over to the counter and paid for my shopping.

I am in London; my wife is over in Paris.

I walked over to the counter and paid for my shopping.

In the above sentences, is "over" really necessary?

Thanks again for your kind help.

It could be if the intent is to focus on the separation or distance.

One can also use words like 'up' and 'down'. In British English, maybe others, you can use 'up' when you are referring to another, higher place, and 'down' if the other place is lower. This applies both to geographic height and relative importance, e.g. London 'higher' than somewhere outside, and the north of England is 'higher' than the south, thus I go up to London, I go up to Manchester (from somewhere in the south). I go down to the sea or river.