There are at least three legal ways to do this. CB radio, ISM frequencies and amateur radio. I say legal because the radio spectrum is heavily regulated because every transmitter affects everyone else to more or lesser extent.
You can buy CB or ISM band radios and get started.
Amateur radio is a better option in my opinion. There are many more frequencies to experiment with, people who can help and people to talk to.
Amateur licensing is different in each country, but an introductory licence is often no more than a weekend course and exam. I know of nine year olds who have done this. It’s not hard. No Morse code required either.
With such a licence in hand you can use things like JS8Call, CODEC2, Olivia, WSPR and hundreds of other protocols to communicate using just a radio and a computer.
Disclaimer: I’m a licensed amateur in Australia and have been since 2010. I hold an introductory licence, here it’s called a Foundation licence, and have been having an absolute blast with all that I can do.
If you have specific questions, don’t hesitate to ask.
As it happens, every person is an influencer, regardless of followers (…) or content.
The people who are influenced, or said differently, the sphere of influence is dependant on random factors like content going viral when it unexpectedly gets liked and reposted by others.
If you’re asking what size of influence generates income, the answer depends on who is paying.