How can I create a transaction without inputs and it will be broadcasted but of course won't get confirmed? I would like the simplest method to do this
This is not possible. Only the coinbase transaction is allowed to have a null, or non-existent input, and the only way to create that is to mine a block. Moreover, it must adhere to additional rules, such as the inclusion of the block height in the coinbase section of the vin (the scriptSig) as per BIP 34.
Unless you happen to run a mining pool, or have enough hashpower to solo mine a block, you cannot do this.
Creating a transaction with no inputs whatsoever is not possible without a hard fork.