It doesn't work like this.

The bitcoin themselves are never "in" your wallet or "on" your computer. The bitcoin never leave the blockchain. All that your wallet stores are the private keys necessary to allow you to tell the network how you want to spend or move those bitcoin. If you copy your wallet file, then you will have two wallet files containing the same private keys which will both have access to the same bitcoin on the blockchain, but the bitcoin themselves are not cloned.

Think of it like if an attacker cloned your bank card. Both the original and the clone can spend the same money from the same account, but the actual money in your account is not cloned.