Please don't use all those question marks. It's not necessary.
Yes, you will will be able to make calls and send and receive SMS.
First check to see if the device is already unlocked. It might be.
On the phone go to Options - Advanced Options - Sim Card - type MEPD and read what it says next to Network.
If it reads "Inactive" or "Disabled", then the phone is already unlocked and you can just put in your SIM card and call and text.
If it reads "Active", then go to this forum. BlackBerry Unlocking - BlackBerry Forums at CrackBerry.com
Contact one of the unlocking vendors.
Get a code either by purchasing one or getting one for free when those are offered.
Enter the code on the device following the instructions included with the code.
Note that if you are "not techy" and if you ever want to use BlackBerry Data features, you would be better off getting a device supported by TMobile.
But if you are only going to use phone and text, then you will be fine.