It has been a while...
As said above, the amateur radio license issued by the federals will allow you to legally operate on certain and specific rf bands.
And they are quite useful.
Probably the first step to take would be to search out the study questions for the entry-level codeless technician class.
A few weeks of studying that, online, and taking the quizes will teach you quite a bit and give you sufficient information to take the official test and get your technician license.
That, is only a beginning.
I would advise you continue your studies and at least get the General class license, which is far more useful for legal, global QSO's.
Do not attempt to operate without first getting a license.
All you may wish to QSO with are bound by terms of the license, and they will not speak with you on the air unless you are properly licensed for that band.
It is totally regulated, and sometimes very seriously enforced.
Most hams may seem to be a bunch of crotchety old duffers at first, yet I have never met one that was not quite helpful.
That being said, you shall discover that 90% of QSO's amount to little more than signal report, equipment discussion, the WX report, and more discussion about antennas.
I would encourage you to learn Morse Code.
Amateur radio, and Morse Code, can be a vital means of communiction when no other method is possible.
End cost may be as little as $400-$500.
You will learn a lot !!!
Best
rc