Early Years Teacher here, how fabulous that you have such high aspirations for your first child! Congratulations on the pregnancy. Your baby sounds so loved already.
I am sure you are aware there are so many steps between 5 months gestation and learning to read. Reading is a higher order skill. The greatest preparation for learning to read is being a good communicator. Encouraging a vast vocabulary by sharing in your child’s exploration of the world, reading and singing to your child daily and taking part in “ping pong” conversations with them (and teaching the art of conversation!)
Maths is all around us. Even by 6 months your baby will be noticing 1, 2 and “more”. The best way to build mathematical awareness is by talking about it and drawing baby’s attention to the very basic concepts they are processing. Verbalising it succinctly to help your child make sense of what they know. I encounter a lot of children who have been coached to count to 100, but can’t reason simple things like, “I have 5 cars. You moved that one to the end of the line but you didn’t add or take away, so there are still 5.”
Toilet training wise, cloth nappies have worked for our family to encourage early toilet training as babies are more aware of what’s going on as the feeling is not being wicked away. Elimination communication can also be started from birth (though I start from sitting up). Other parents have great success with the similar Montessori toilet training method.
I would also like to state that along with communicating (as a precursor to reading and maths) your child’s physicality should not be overlooked. Basic things like crossing the midline to support coordination and engaging the vestibular system to support regulation do SO MUCH for ensuring children are ready for school.
However, do not put too much pressure on yourself. This is a surefire way to create an unhappy home. Instead enjoy exploring the world with your child. TALK TO THEM.