I know what resistance is and I know how to check it. What I don't know is what kind of ignition you are talking about, it sounds after market w/ after market coils?
Resistance is calibrated in Ohms. It is checked with an OHM Meter or a Volt/Ohm meter (also called a VOM). Sometimes they are called Multi Meters because they check multiple functions. They may include Amps and/or Temperature but neither of those last two mentioned are important to you at this time or will ever be of any use on working on vehicle electric systems.
Do you have one of these Meters? The cheapest come from Harbor Freight and users claim they work just fine. You can get one at HF for probably less than $20. I have a little better meter from Sears, it's a Craftsman Brand. I don't remember what I paid but the modern meters are much easier to use than what we had even 10 years ago. Auto Ranging is a nice feature and most modern meters have this. You will almost invariably see only digital readout meters. The older analog dial gauge is probably hard to find.
I have a small VOM I carry in my tank bag for longer trips. It is not much bigger than a credit card except it is thicker. Very small for a VOM. I bought it years ago at Radio Shack and I think it is their brand but I also don't think they make this anymore.
If you installed this after market ignition (what is it again? I keep forgetting, or you never say) I would carefully check the wiring. If these parts are even momentarily hooked up backwards they will not work. And even when installed correctly if they were temporarily hooked up backwards they will not work.
The figure the guy on the phone gave you is 2.4 to 2.8 Ohms.