I believe all the following has applied since the beginning and is still what happens.
The mining reward is not given when starting to mine but is allocated when each block has been successfully mined.
The miner chooses what happens to the mining reward. They include as the first transaction in a block a special "coinbase" transaction that has no inputs and at least one output. The sum of the outputs cannot exceed the sum of the currect mining reward plus the total of transaction fees offerred by each transaction they include in that block.
The mining reward cannot be spent until 100 further blocks have been mined (by any miner) in a chain including the mined block.
The mining reward halves every four years roughly.
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