Evolution is very logical and not difficult to understand. You don't need to be an expert . Just listen to your biology teacher. To make it easier to understand, i will use some facts that are not controversial at all.: 1 Our bodies (and all living creatures) are built up by cells. 2 The cells contain DNA molecules that build up our genes. 3 Genes are unique for every living creature (exception are twins that grew from the same egg of the female) 4. The genes we get depend on what genes our parents had, but we will never get exactly the same genes as out parent. 5 Different gens means we are not same and we can impossibly be equally adapted to life. Some our better at running, some better at thinking, some better at something else.
These differences is what evolution work with. It is maybe not important if we have curly or straight hair, but in a world where an animal needs to hunt to get food and flee to not be eaten, it is very important to be smart, or if not smart than be able to run very fast. This is what evolution works with. Natural selection is not something that a god is choosing. Simply, the best ones survive and spread their genes to the next generation. It is very logical and it is not difficult to understand at all. Best regards: Charlie :-)