How do you find the number of molecules or ions of 2.00 mol Fe^(3+)?

You have quoted a $2$ $m o l$ quantity, this is $2 \times 6.022 \times {10}^{23}$ $F {e}^{3 +}$ ions.
You can use the mole as you would any other collectve number, $\text{dozens, scores, grosses, centuries}$. If I have one mole of stuff there are $6.022 \times {10}^{23}$ individual items of that stuff.
You have $2$ $m o l$ of $F {e}^{3 +}$ ions, and thus $12.066 \times {10}^{23}$ $F {e}^{3 +}$ ions.