I need advice on how to wire up some LEDs?

I'm trying to custom wire up a toy plane for a nephew, and I'm not the best at knowing exactly what I need for the wriing. Specifically if theres a certain way I have to do it, and what resistors to use (and where).

So I could do with someone who knows what they're talking about to help out?

So theres a hatch at the back I'll be able to take a battery pack in and out of.

Inside, I'll need (LED sizes based on best guesses as to what will fit - don;t know if they actually exist in these sizes):

two large lights, maybe 1cm wide each, and two smaller - roughly 4mm wide LEDS.

They're be a further 2x 4mm LEDs on each wing.

And at the front, 4x 4mm wide LEDs, and 4x 2mm wide LEDs.

A further 1cm wide light on the top, and one on the bottom.

So 18 lights of various sizes in total.

Whats the best way to do this?

Thanks.