You mean types, right? Typing is what you do on a keyboard.
If you want to understand type systems, Types and Programming Languages (https://www.cis.upenn.edu/~bcpierce/tapl/) is the book most people start with. If that is too advanced for you, PLAI (https://www.plai.org/) is a gentle introduction to programming language theory which includes type systems.
Those books are great; though I'm not sure whether they are good for a beginner? Getting your feet wet by programming in a few reasonably typed languages might be better, before you tackle TAPL?
(By 'reasonably typed' I mean something like Haskell, OCaml, even TypeScript or Facebook's hack. But not Go, C++ or Java.)
If you want to understand type systems, Types and Programming Languages (https://www.cis.upenn.edu/~bcpierce/tapl/) is the book most people start with. If that is too advanced for you, PLAI (https://www.plai.org/) is a gentle introduction to programming language theory which includes type systems.