Controling Mosfet by 3,3V Raspberry Pi GPIO Pin
First, you need to give the LED it's own circuit, like this:







simulate this circuit &ndash; Schematic created using CircuitLab

The MOSFET you have chosen, though, will not work for this circuit; from the datasheet:



If you look closely, the threshold voltage (which may be as high as 4.9V) is specified at a drain current of \$255 \mu A \$.

To fully turn this device on, you need 10V \$ V_{gs} \$ drive so it is not really a logic level FET.

There are devices that will do what you need; in manufacturer parametric tables such devices have \$ R_{DS}{(ON)}\$ tabulated against various \$V_{gs}\$ drive levels.

Look for a device that has a 2.5V \$V_{gs}\$ drive capability.

Likely sources are Vishay and Diodes Inc to name but two.