This is the 8363rd most frequent Russian word.
молодого
"Молодого" means "young" (genitive or accusative singular masculine or genitive singular neuter form).
The word 'молодого' is used in the genitive singular masculine form to describe 'человека' (person), indicating the possession of youth.
Я встретил молодого человека в парке.
I met a young man in the park.
Here, 'молодого' is in the genitive singular form, qualifying 'козлёнка' (a young goat), to specify its youthful attribute.
Они купили молока от молодого козлёнка.
They bought milk from a young goat.
'Молодого' appears in the genitive singular form to denote the adjective describing the driver ('водителя') as young, forming a possessive relationship.