Simple electric circuits shouldn't be hard for those of average intelligence. Just remember two things: it can kill you if you touch a live wire, and to always unplug before you work on it.

The fan goes in parallel, just like all the lamp holders -- black to black, white to white.

The switch goes in the "hot" wire -- black (brown in EU) is hot, like burned stuff, white (blue in EU) is cold (neutral, return) like water, ice and snow and green like grass (with yellow stripe, like my lawn) is ground.
Now, with lamp cord, the one with the stripe should be hot, but only if you have a polarized plug on the end. That may be the only reason to use a 3-wire cord: so you always switch the hot. It's OK to leave the ground unconnected if you have no metal to connect to. Bring the cord in, connect the black wire from the cord to one side of the switch and the black wire from all your light fixtures and the fan to the other side of the switch. All the whites connect together and to the line cord.

You'll do fine.