If you have internet access, there are free calling app available for getting local number & receive/make calls to USA/CANADA.
For international call, buy the pack dial91.com or equivalent who gives you 100 mins for 1$.
If you cant have internet access all the time & still want to have phone connectivity, buy SIM.
Most companies offer at 10$ price.
Watch out for any initial set up cost. Some may charges 15$. You dont want to pay for it.Bell/Rogers/Fido almost all have same plan starting like local 200-300 minutes for 25-30$.
Alternate option is to buy SPEAK OUT SIM from 7-11 stores. good thing about it is you can recharge as minimum as 5$, and it lasts upto a year. so if u just want to retain SIM for emergency, this is good bet.