So you would like your family to pay international plus cell phone rates to call you? That's very nice
The system in Canada doesn't work like that. Actually it's the same in the US as well.
In Canada, the privilege of having a cell phone is that you pay to call other people and you also pay to receive calls. The people who call you do not have to know if it's a cell phone or home phone number that you gave them. They pay a local fee to call you regardless.
What you can do regarding cell phone plans is shop around for a plan that suits you. Some companies will offer you free incoming but you can be sure you'll be paying for that in your monthly fee. Also if you have a monthly plan, many companies will add this $6.95 access fee every month which you don't pay if you are on a pay as you go.
If you want to keep using your UK phone, you can do that with a Fido or Rogers SIM but if you go to another company, they don't use the GSM system, rather something called a CDMA system and you would need to buy a phone from that company and it will not have a SIM, it will be programmed for you at the store.
If you later want to change companies, the new company will want you to buy one of their phones so it's not good to switch often. Some people will get a phone cheap on a 2 or 3 year contract and then just look at it again when the contract it up. To find a fitting plan, you have to look at your phone use and research all the companies plans to find out which one suits you best. Then get a phone from that company and stick with that plan.
If you find no good plan for your current cell phone use, you might want to consider changing your phone use. You can get a landline without the bells and whistles for $25 a month. It will allow you to receive as many calls as you want for free and all your local outgoing calls are included too. This is what I ended up doing and just kept a pay-as-you-go phone for $10 a month for my very limited cell phone use.