Okay - that's a bit more clear. Try a new bulb in RH light then. That should deal with headlight problem straight away. You have a knackered bulb.
The other is a separate problem that needs sorting out. To do with your rear light clusters; they get full of mank and deterioration and the connectors are somewhat flimsy. Open up the rear lights and check all connectors:
- Red wires for brake lights
- Green wires for indicators
- Grey for reverse lights
- white for tail lights
So specifically check out the red and white wires. They really do get manky and a good session with a Dremmel cleaner soldering iron, sorting out any frayed wires sorts stuff out. For the cost of new bulbs, now would be a good time to just go ahead and change them. Good time to also clean up the old lenses and stuff.
Don't worry about indicators, reverse lights and interior lights. They're all completely separate from this issue so won't be affected.
If the above doesn't work, get back to me again because you might want to check out your brake light switch. But see if the other works out first!