Designing a high frequency amplifier and needing an oscilloscope
To test your amplifier at 1MHz, place some feet of wire on the input, and connect output to the screw-terminal of a standard AM/FM stereo receiver.
You'll likely also need to bring over the GND of the amplifier to be the GND for the AM/FM radio. You thus examine 540---1620KHz.

You can certainly repeat this for FM, getting to 88-108MHz. If the AM is clear as you monitor several stations, and the same clarity is found for the FM stations, you have high confidence there is NO OSCILLATION in your amplifier.

And if the various stations have made it thru your amplifier, particularly in a station-dense urban environment, your distortion (at least the 3rd order, where uniformly spaced stations will trash each other) is good.

You can inject a strong audio signal while examining AM or FM clarity. Vary the audio signal frequency. If you hear no effect on AM or FM, you gots a fine amplifier. IMHO

Your garage door opener might radiate at 433MHz. Or not.