If it helps, I had that problem myself when I first tried Fallout and Fallout 2. Simply drag the item into your equipped slot (Where you'd put weapons and stims.) Then when it's there, click on it while in the normal view as you would your weapon.
THiS.
OP, don't be embarrassed. Even though the original fallout games are awesome, the mechanics haven't aged well. My worst experience was trying to use a rope to climb down one place. Spent an hour trying different things and when I finally consulted a walkthrough, it turned out I was doing everything right, I was just a pixel off target.