I will go to see my in-laws with my wife in the late afternoon.

'to see' is also correct, but just saying 'see' sounds more native

As usual, we will sit under anthe outdoor patio umbrella in the garden.

I enjoy listening to the sound of the pitter-patter of the rain while tastdrinking tea and chatting.

'tasting' makes is sound like you're trying different kinds of teas, tasting is usually uses for first experiences of eating/drinking something

The melody of the piano is magical for me, though I know nothing about it.

We have aIt's raining light rainly today.

We usually use 'it' with weather expressions.

I will go'm going to see my in-laws with my wife in the late afternoon.

Your sentence is good too.

As usual, we will sit under anthe outdoor patio umbrella in the garden.

It's a specific umbrella, so 'the'

I always enjoy listening to the sound of the pitter-patter of the rain while tastsipping tea and chatting.

Pitter patter is onomatopoeia so it's clear it's a sound. Taste is the result of sipping. Sipping is the action.

There is a small creek near my house, t. The smell of the water passes me and makes me feel soothed(often?) wafts by and calms my nerves.

Sounds like a repeated action since you live there

If I am lucky, I might hear my neighbor's daughter might also be practicing piano.

The melody of the piano is magical for mehas a certain magic to it, even though I know nothing about it.

InUnder the Umbrella

I think this might be what you mean? "Under" makes more sense than "In"

There is a small creek near my house, and the smell of the water passes me and makes me feel soothed.

Or you can use a semi colon instead of "..., and..."