Unfortunately, you cannot be assured that you will be able to enter Canada, except in certain circumstances such as if the offense happened while you were a minor, or if at least five years has passed and you have only committed one crime. In your case, you've committed two and the time period before you would be deemed rehabilitated will be longer. Details can be found here. In fact, having had more than one conviction, you will not be eligible to be deemed rehabilitated by simply appearing at the border, although you may be if you apply for a visa. The previous link discusses how this works. Your convictions will need to be at least ten years old before you would qualify for any consideration here. (It is questionable whether deemed rehabilitation is even available if there is more than one conviction.)
If you try to go, you should be honest if asked. Understand that if the convictions are discovered, you are likely to be refused admission. Understand that if you lie about them and are caught, you are likely to be given a very long-term or even permanent ban on entering Canada.
You can apply for a temporary resident permit at a cost of CAN$200 - if granted this, you will be granted entry. However, if refused, you are not refunded the application fee. You must demonstrate that your visit to Canada is beneficial to Canadians, over and above the risk that you present.