variable in SQL INSERT

I'm new in SQL language, i would like to know how can i made this code working. Because it don't understand that $lala and $lolo are variable.

        $lolo = "ahha";
        $lala = "2";
        $sql = "INSERT INTO organisation (id_orga, nom) VALUES ";
        $sqll = '($lala, $lolo)';

        $resultat = $conn->query($sql.$sqll);

so i tried

        $lolo = "ahha";
        $lala = "2";
        $sql = "INSERT INTO organisation (id_orga, nom) VALUES ";
        $sqll = '('.$lala.','. $lolo.')';

        $resultat = $conn->query($sql.$sqll);

But both code doesn't INSERT in my BDD and give no error