Welcome to Android Central! For that kind of thing, you typically have to do a factory reset. If Tecno doesn't give you a way to recover your password (which would typically be if the password were saved to an account in the cloud, rather than directly on the phone), then you won't have any other option.
Since it sounds like you might be prone to forgetting important things like this password, this might be a good time to make sure you have a way to remember or recover even more important passwords/PINs, like the one to unlock your phone, or the one for your Google account. I suggest either using a good password manager like LastPass or 1Pass, or simply writing your passwords down and keeping them somewhere safe at home.