I have a question regarding deploy smart contract on different blockchains like ETH, BSC, etc I see some tokens already on many blockchains and I don't know how it's work I know I can deploy same contract on many blockchain but my questions, How they control the price on different blockchains and Should develop bridge between these chains?
Every sidechain or layer 2 chain has their own bridging system. In order to bridge an asset, you build on the native bridging primitives for the involved chains. There are also liquidity-based bridges like Hop that work differently but require a bridged token to already exist on the destination chain.
I'd suggest looking up the documentation for the chain that you're particularly interested in, and going to the bridging section.