i got a question about how to move currency between exchanges ?
You can withdraw a cryptocurrency from exchange A to exchange B. Withdraw from A and deposit it to B but you will have to pay withdrawal fee charges by the exchange A. Check withdrawal fee and how much is it for your withdrawal value before doing your withdrawal.
for example i buy BTC/GBP on 1. exchange and i wont to move this to another exchange - what will happen on the other exchange if they support BTC/GBP pair will this be visible as BTC/GBP ore as BTC/USDT ?
You can not move trading pair. Listing trading pairs is a rights of each exchange and they are totally responsible for what they list, what they don't list.
Even two exchanges have a same trading pair, their price rate can be different because of trading volume, liquidity for that trading pair as well as order walls and trading activities of buyers and sellers on those exchanges.