You must not break the law with a poor quality high power transmitter because it causes all kinds of interference to aircraft communications and guidance signals, FM radio, TV, police, ambulance and fire department radios.
Make a radio instead of a transmitter as an intro to RF.
I began playing with electronics about 55 years ago. I built an AM radio about 51 years ago. I built an FM tuner and amplifier about 49 years ago and I built an oscilloscope about 48 years ago. I built a low power FM transmitter about 47 years ago and built a much better one 6 years ago. My entire career was in electronics, mostly sound systems.