Honda designed VTEC engines to not be noticable when when it kicks in.
So before you get going on how to add VTEC, be sure you don't already have it. All 2000 Civic EX 2-door coupes came with VTEC.
Look on the trunk on outside of your car. If there is an "EX" emblem on it then you have VTEC.
You can also look on the engine block for D16Y8 stamped in the front where is faces the radiator. It's down below where the upper radiator hose connects to the cylinder head.
I highlighted the stamp on my engine.
Another way to tell is to look for the VTEC solenoid on the cylinder head. It's just behind the distributor facing the firewall. It looks like this:
It's the part with the green plug on the bottom and the cylindrical part on top.