There is an important thing to remember while teaching a toddler. It's be careful on what you put inside their minds because it is the stage where they are the most adaptive. There are also various and specific topics that needs further research in teaching a toddler but I am going to put general information that can help a fellow parent. I am not a child development expert but here are some of the learnings, realizations and advices that I will share to everyone.
I started to teach my son academically when he turned two years old. We started from knowing what's his name, what's his parent's name, recognizing colors, identifying shapes, counting numbers and familiarizing with the alphabet. He easily knew it all except the alphabet. At first, it is frustrating that our children are not able to understand what we are trying to teach them. But worry less because children are different from each other and has their own strengths.
I noticed that he likes to play outside more. So, I let him discover more of his interests and that's where I would start a new teaching. From riding a bike, and using a kiddie scooter, he didn't learned it all in a snap. We started by identifying his left and right, how to push a pedal, or how to move his foot upon riding a scooter. In every lesson, outdoor activities or academics, I advise parents to coach their children from the very first steps up to the next detail by detail. Because they couldn't understand vague ideas. It's easier if you do it first and let them imitate you.
In terms of manners, it is best to teach a child when you are practicing what you preach. As a parent, we should also say respectful words to them always. In that way, they can adapt to it positively. In our household we always say "sorry", "please", and "thank you", to each other. I also taught my son to say what he wants or needs and not just point out and cry at everything. Saying sentences like "I need help", "I'm hungry", and "I want to play" help us understand their feelings more. Slow down and continue to asking questions like "How are you?" or "What are you doing?". In this way, children can practice their communication skills.
Explore different activities and speech practices that both parents and children can enjoy. And remember to always make their studying or learning time a playful one because they are most interested when they think of it as playing. No pressures, just pure interests.