Hello Ayzatoronto,
Welcome to the community!
Unlike post-paid services, there is no temporary suspension or freeze on pre-paid accounts. However, since your account is pre-paid, you should be able to simply not pay for services during the months you will be away (see here).
I understand you do not wish to lose your phone number. As FidoKenny noted in that thread, not paying services for few months won't likely be an issue. That said, while FidoKenny noted that accounts would be cancelled after more than 365 days of continuous inactivity, the Terms of Services states that if your pre-paid mobile account balance remains at $0 for 6 consecutive months, your phone number will be deactivated (sec 7c). I'm not sure whether deactivated is different from cancelled. If you are away for 6 months or more, you might consider verifying the length of time before potentially losing your phone number.
Generally, in order to prevent roaming, people often disable data as well as roaming data. However, roaming data is not available with pre-paid accounts anyways. It should be noted that disabling data and roaming data does not prevent voice and/or message roaming. It is also usually recommended to enable Airplane or Flight mode on your device for the duration of your trip. You could manually enable Wifi when required.
Hope this helps 😀
Cheers
