I believe the right-side lights are Fuse 7. If it's the fuse your right brake light shouldn't work either according to the diagrams in the service manual (I've never had this problem in real life, so someone correct me if I'm wrong).
The fuse box is on the driver's side in the engine compartment, at the "back" if you're looking down at the open engine compartment. The cover will probably have an irrelevant air conditioning system warning sticker on it. Remove the cover (it just pulls off) and it's pretty easy to figure out which fuses are bad. There are spares in the box.
I don't think that fuse has anything to do with your gas gauge, though, sorry...