The ban is a matter of law based on the facts of your situation. You can look at the law and make your own determination about whether you are currently under a ban based on the facts of your situation. Various bans have various durations, specified in the law.
You can't ask the US government whether you currently have a ban -- in many cases they don't even know (e.g. you could have a criminal conviction abroad they don't know about that causes a ban for crimes, or they may not know exactly when you left because there is no record of people leaving by land so they can't determine whether you have an unlawful presence ban, etc.), until you try to apply for some benefit that requires you to be admissible (e.g. a visa or ESTA or entry), at which time they will examine the facts of your situation (which are asked about on various questions on the visa application, for example) to determine whether a ban currently exists according to the law.
Based on your description, you triggered an INA 212(a)(9)(B) 10-year unlawful presence ban when you left the US (in about 2000?) after having accrued more than 1 year of "unlawful presence". That ban would be long over and so is not relevant now. Nothing else from what you have said indicates you might have any other bans, but it's possible you may have other bans from issues you have not disclosed (e.g. criminal convictions, drug use, etc.).
Having overstayed on VWP in the past makes you ineligible to use the VWP ever again, according to INA 217(a)(7). So you must apply for a visitor visa to visit the US (unless you become a Canadian citizen, as they don't need US visas).
Not having a ban doesn't mean you will be able to get a visa and/or entry. Many foreigners who have no bans get denied visas and/or entry all the time. The officer can always deny visa and/or entry for the generic reason of "failing to overcome the presumption of immigrant intent". This determination is made anew each time you apply for a visa and cannot be predicted ahead of time.