How do you check spark timing? And how do you clean the throttle body? (or check if it needs cleaning)

I've had the car a few years, but don't know the maintenance before me, so I'd like to kinda do it all. I just replaced the air-filter, and have recently done plugs.

Is there an easy way to check the hoses? Just make sure they're not leaking? Is it common for these to break?

I was also thinking about flushing my transmission fluid, is this complicated at all?

I'm planning on doing distb. cap & rotor too, I just helped one of my friends replace his in his Teg. If mine aren't particularly bad, will this make any difference? Or are they like wires and I should keep them stock until they break?

Everyone has been a lot of help, thanks again.