There is nothing to prevent you from marrying your fiance(e). As long as they can get an eTA or visa to come to Canada, you can marry them here.
A criminal record doesn’t normally prevent you from sponsoring your spouse. There are only certain types of convictions that would affect your sponsorship application:
- If you were convicted of a violent or sexual offence, an offence that caused bodily harm to a relative, you are ineligible to sponsor.
Otherwise, your criminal record should have no affect on your application.