Is it possible to create an arduino RFID card reader able to read the signal over 30 meters?
If there are some methods, can you explain me how i can do and what are the materials to use?
The RFID reader must transmit the energy to the tag, which then is used to transmit the stored data back to the reader. For spanning 30m you'll need kind of a microwave oven for the energy transfer, that fries everything near by.
The only chance for bigger distances are active tags, with their own power supply (battery, solar panel...), which listen for a reader signal and then send their data. Bluetooth is kind of such a transmission protocol, but usually also (intentionally) with a very limited range. What do you expect when multiple such tags are in range?
Active RFID can reach a few meters. Passive RFID (as #1 describes) usually just a few cm.
30m is a long distance. That's more the realm of NRF24 or WiFi or Bluetooth or, well, that kind of radios.
In theory it should be possible to do it passive over a long distance - a couple hundred km can be done and has been routinely, but the technology is now kinda obsolete: AM radio & crystal receiver. Listen to the radio with just the power transmitted by the radio waves. Enough power for old fashioned headphones must be enough power to run simple modern electronics. Of course those transmitters are typically in the order of a couple hundred kW...