Types
Go is a strictly typed language. However, there is some level of flexibility with interfaces.
Don't get too weighed down on learning each particular type. It will become more obvious as we build things.
There are built in types (which have some correlation to types you might have seen in other languages). For more detail on built-in types, you can skim this go101 page: https://go101.org/article/type-system-overview.html
You can also create your own types with structs.