The first person to receive bitcoins was Satoshi Nakamoto the creator of bitcoins back in Janaury 3rd, 2009. We call the first block the Genesis Block and it contained a special string to prove its date of creation:
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He was unable to spend the 50 btc he received because the coinbase transaction was never added to the global transaction database thus the first coins that were spendable were in block number 1:
https://blockchain.info/block/00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048Is all the meta info about the legendary block number 1.