Learn how information is transmitted
I want to know if it is possible to use another electromagnetic wave, like visible light, to send information.

Yes it is, you undoubtedly already know that WiFi exists, there's a similar (but still somewhat experimental) technique called LiFi

It is no surprise that light can be used to transfer information. Light and radio waves are both EM (Electro Magnetic) waves. Light is "just" at a higher frequency and our eyes are sensitive to it.

Also, fibre-optic cables have been in use for a long time and also use light for transporting information.

How to learn: just start reading some books and browse online. Also youtube might have some videos explaining things. Just follow your interest. This is a broad subject and how deep you want to go depends on your interests and what you need. To really understand how for example Television works (and be able to explain it properly) could take years.