These are all great questions but I think some of it you will find to be intuitive. Music is something babies can hear in the womb.
Be careful of volume and little ears.
How many decibels is safe for a baby? Because your baby cannot tell
you how loud is too loud, use a general rule of thumb, that noises
less than 80 decibels should not cause hearing damage, according to
The Children's Hearing Institute. This is the equivalent to noise in a
restaurant or in city street traffic. A normal conversation is about
LINK How many decibels is safe for a baby?
Week of Pregnancy/ Development
9 /Indentations appear where baby's ears will grow
18 /Baby starts to hear sound
24 /Baby is more sensitive to sound
25-26 /Baby responds to noise/voices in the womb
If you speak more than one language it works very well for infants. LINK Though it at times seems as if the infant is confusing the languages, the research shows that is not the case.
Coding is maths, organisation, and patterning. These are all widely encouraged by the toys made for infants - toddlers -- stacking toys, colour matching -- this can later include letter/number/shapes and item matching and ordering. "Put all the red items here and the blue there." The level of difficulty is added gradually by adding colours and shapes and so on.
Talk to your infant as if they can respond. "I am making your lunch. I am heating your peas. The peas are green. I like to eat peas. You are eating the green peas. They are small and round." Anything like this will help your child in the long run. Even things they have no reason to know, like your own reading is a good way to keep the language coming. Your car magazine works as well as your fashion mag.