A character’s race is a matter for the creating player’s choice, from all the races for which the character qualifies by virtue of his or her ability scores. It is possible for a player voluntarily to lower an ability score in order to qualify for a desired race, but not to raise it for the same reason unless the GM grants special permission.
A note on starting ages and aging: It is a matter for the GM’s discretion whether to adjust a character’s ability scores based on the character’s age. Some GMs add to constitution, and sometimes strength, and subtract from wisdom for younger characters, and make the converse change for older ones.
A note on racial languages: Demi-humans usually begin with several “free” languages. None may learn more than two additional languages over and above these, however, irrespective of their intelligence, save elves, who may learn three languages if their intelligence is 18.