In a resonance circuit, where do you connect the terminals of CRO to check frequency being produced?

If the oscilloscope is capable of displaying 100MHz or so, it is only necessary to hold the probe somewhere near the thing and you should see a signal. Any direct connection changes the frequency significantly because of the capacitance of the probe. The probe capacitance is ~15pF for a divide by 10 probe, and ~150pF for a divide by 1 probe. As you can see the capacitance used is of the same order. Only 1pF of capacitance has a reactance of 1590 ohms at 100MHz, so the very small capacitance between the probe and nearby objects results in significant coupling.. I would expect to see a few tens of millivolts on the CRO.

I doubt it will do any significant jamming, but it is good experience to try to make such a thing. It would quieten the receiver noise if you can tune it in, and the frequency will change when you put your hand near it. Construction needs all connections to be short and direct. The low power AM transmitter shown in the link is a bit simpler to get going because the stray components have much less effect. It is less fussy. A 200uH inductor? With a paper towel tube of 42mm diameter as the coil former, wind very smoothly 100 turns of enamelled wire about 0.5mm in diameter. This should end up about 60mm long. For 1mm diameter wire it would be about 140 turns taking up 150mm. That is approximately 18AWG. You can also use a fixed capacitor for the tuning, but it should be an NPO ceramic type between 100 and 300pF.

Approx freq:

f = 1 / (2 * Pi * SQRT( L * C)) = 1 / (6.2832 * sqrt(220pF * 200uH)) = 758kHz

It will probably be lower in practice due to the loading of the other circuit parts. Where it says condenser mike it means electret mike. Look these up for the connections of 2 or 3 wire type.

Hi that is because this simple jamming device needs a pick up coil linked to the L1 component so you would need a few turns of copper wire wrapped around that coil to couple it up to a CRO.

how ever a 2n 2222 is not going to jam very much only a radio next to it.

The best place to connect the scope is at the emitter of the transistor. It is a relatively low impedance point and the scope loading should not be a problem.