Bulb: try a shop that sells bulbs for cars&vans.
Clock: wouldn't expect that the clock has a dedicated fuse, in other words if the clock stopped because of a blown fuse I would expect the whole instrument panel to be affected; but to be sure, you could simply pull out all fuses 1 by 1 and check them.
Odometer: that's a common fault in these vans. Can have two reasons. 1.Some or all of the little bars that make up each digit don't light up because of a fault in an electronic chip at the back of the odometer; dunno whether there is a remedy. 2.The bulb that backlights the odometer is blown; somewhere on this forum you will find how to remove the instrument panel so you can get to the back of it and replace bulbs.
Note that if part of the digits are visible, the bulb is good and the problem must be the electronic chip. If nothing is visible the fault could be the bulb or the chip or both.
