Will this Optocoupler and MOSFET be able to deliver 5V +2A?
You have the wrong coupler

In order to use a N-channel FET here, you need to be able to pull its gate above its source, which your 4N35's transistor output has no ability to do.  What you need instead of the 4N35 is a device called a photovoltaic isolator that replaces the transistor output with a tiny solar cell that can actually generate the voltage needed when the LED shines on it.  The resulting circuit is shown below in its simplest form.







simulate this circuit &ndash; Schematic created using CircuitLab

(Of course, the PMOS high side switch will work for a power switching application, but the NMOS approach is somewhat more efficient/versatile.)