Increase the number of vehicles with Trigger

Question

I have the table pessoa who has the spine qtd_veiculos, every time I give one insert with a new vehicle, which has the CPF foreign_key same as some person at the table pessoa, this column should be incremented by 1, I’m not getting anywhere to do this.

Attempt 1:

CREATE OR REPLACE FUNCTION incrementa_qtd_veiculos() RETURNS TRIGGER AS $$
BEGIN
    UPDATE pessoa SET qtd_veiculos = qtd_veiculos+1 WHERE cpf = new.veiculo.cpf_dono;
    RETURN NULL;
END;
$$ LANGUAGE PLPGSQL;

Attempt 2:

CREATE TRIGGER incr_qtd_veiculos AFTER
INSERT ON pessoa
FOR EACH ROW EXECUTE PROCEDURE incrementa_qtd_veiculos();

P.S.: The database contains vehicle monitoring information.