As you have noted, the bill proposes a range of penalties for the offences. The offence you're referring to in terms of selling is currently under the Controlled Drugs and Substance Act. It's a trafficking offence, and it carries a maximum of life imprisonment. It imposes mandatory minimal penalties.
Under Bill C-45, the offence of distribution or selling would be a hybrid offence, meaning that the crown would have the right to elect to proceed summarily for less serious offences, and to proceed on indictment for more serious offences.
On indictment, the premise is correct that it would be a maximum of 14 years. However, on summary conviction, for an adult who sells to a young person, the maximum penalty would be 18 months, whereas for an adult who sells to an adult, the maximum penalty would be six months.
What Bill C-45 does is provide greater flexibility to the criminal justice system, including the crown and the courts, in terms of sentencing, to proceed in a manner that best reflects the seriousness of the offence. It provides the courts with more flexibility at sentencing to deal with a range of possibilities, instead of an indictable-only offence with a maximum of life imprisonment.