Problem:
You are interested in controlling a led RGB strip with a raspberry but it's not clear how to setup Mosfet because there are people that use 1 resistor, 2 resistors, others without resistors, the scheme is quite different, etc...
Solution:
If you would like to use Mosfet as a switch to control a RGB led strip,it is recommended to use resistors in the gate port, one to the source and other to pump.
I use and old P30N06LE and it works well, as I can see everyone is using the IRLZ34N, it's important to read the mosfet datasheet Gate to Source Voltage value in the mosfet to ensure the volts needed to activation.
Sources:
Without resistors:
https://dordnung.de/raspberrypi-ledstrip/
https://dordnung.de/raspberrypi-ledstrip/
With 1 resistor:
http://www.knight-of-pi.org/color-mixer-control-a-rgb-led-strip-with-the-raspberry-pi-and-the-n-channel-mosfet-irlb8721/
Note:
Take in consideration that using a led strip, it's required to power them with a 12v power supply, if you put any wire in the wrong position, your raspberry pi will die like mine :-)