Hello Roger123,
Do you know what version of the Blu Studio C 5+5 you have? Judging by the specifications listed here:
| 2G bands | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 |
| 3G bands | HSDPA 850 / 1700(AWS) / 1900 - D890U |
| HSDPA 850 / 1900 / 2100 - D890L |
both of those versions (D890U and D890L) have all of the compatible bands/frequencies for 2G and '3G'. If you have a different version, the bands/frequencies may be different.
Coverage depends on the corresponding bands/frequencies on your surrounding cellular towers as not all towers use all bands/frequencies. You can get an idea of your area towers here. Assuming you are in an area of 2G and/or '3G' coverage, you should be able to use it for calls and text messaging without issue.
You might need to verify the phone is using the proper APN. Since the phone is not LTE-capable, it should be using Fido-core-appl1.apn. You can verify those settings here.
I believe Blu devices are unlocked, however, you should verify that your device is unlocked.
Hope this helps 
Cheers
