On the side of the tire you have an indicator for the Thread left. It's called TWI, thread wear indicator. Once it's on level with the surface that touches the road, change tires.

Tires are cheap but don't cheap out

I use the trip B counter to know when I'm over the 500km. Usually around 800 it gets very noisy and harder to manoeuvre it by hand.

If chain has sand or dirt I use the Honda chain cleaner, otherwise just put more Honda chain lube on every roller on the inside of the chain( on the bottom part of chain lube the roller from the top). You don't need much lube, specially if you put it on the inside, with the centrifugal force it will spread it around.

Afterwards rotate the wheel couple of times with a paper towel resting against the outside of the chain to remove some of the old lube.

Love the feeling of pushing by hand a newly chained bike and the silence when coasting