Stream Audio and WebCam Video through Radio Frequency
The internet is different than the radio spectrum: you explicitly need a license to transmit in any radio band!

With Wifi, Bluetooth and the like, you buy devices that are tested to only operate in so-called license-free bands, where an exception to that rule exist.

Since you're not a radio engineer, you'd not start by trying to build a device that fits into the legal framework of Italy / the EU / ITU region 1 (hint: it's hard to do that, also, such devices are expensive to build in single quantities).

Instead, you'd use an existing system (e.g. Wifi routers) to connect.

You've just added this comment:


  We are 20 km away from each other.


Not going to happen, even if you were a radio engineer: To transmit live video, you need many bits per second.

To transmit many bits per second, you need good signal-to-noise ratio at the receiver.

To get good signal-to-noise ratio at the receiver, you need much transmit power to bridge 20 km. (There's mathematical bounds on that – nothing you can do to cheat that!)

That much power is not allowed in the license-free bands.

So, this is impossible to achieve.

Your cheapest option and best bet is getting a license for a point-to-point microwave link, and stock equipment for that. That's going to include a high tower, and at least 1000€ in RF equipment (very likely more).

Guess who has such licenses, equipment and towers? Companies operating mobile phone networks. They, for a relatively low price, sell you access to their network :)