https://pragprog.com/book/swdddf/domain-modeling-made-functional https://pragprog.com/book/swdddf/domain-modeling-made-functi... is a great book to get started

https://pragprog.com/book/swdddf/domain-modeling-made-functional https://pragprog.com/book/swdddf/domain-modeling-made-functi... is a great book to get started with. Unlike most books on FP it doesn't start with an academic or mathematical approach but rather focuses on how to use FP to make solving every day 'business' programming easier and less error prone.