What if using "to" instead of "get"?

Question

I can't understand the what does followings it mean. What is the role of "get" there? Why we don't use "to"?

get started - to start
get confident - to be confident
get married - to be marry

Answer 1

This usage of “to get [adj]” is roughly equivalent to “to become [adj]”.

In the case where the adjective matches the -ed form of a verb that indicates a change of state (such as “to start”, “to marry”), it is also roughly equivalent to that verb, but with more of a focus on the change itself rather than the end result.

However, sometimes the adjective isn’t like that (such as “confident”), and there is no simpler way to say it.

Note that “to get (or become) confident” is not the same as “to be confident” because that adjective (at least by itself) doesn’t denote a change of state.