I would recommend the book "What is Mathematics" to you. It covers a wide range of math topics from first principles. The beginning of each chapter is light rea

I would recommend the book "What is Mathematics" to you. It covers a wide range of math topics from first principles. The beginning of each chapter is light reading, but gets more rigorous as the chapter progresses. It talks about mathematical notation a good amount, which is surprisingly helpful because many math ideas are intuitive but hidden behind extremely inaccessible notation. The Kindle version has bad formatting, but the Google Books version works well on all devices supported by Google Books.