Remember that each fund is unique and hence exposed to different levels of risk. Some are relatively low risk, whilst others can be very risky and those will only be appropriate for more sophisticated investors.
The value of your investments, and the income derived from them, may go down as well as up. You may not get back all the money that you invest.
You will pay a fund manager fee for the management of your investments, and a platform fee to TD Direct Investing for the administration of your investment.