first things first
used to say that something should be done or dealt with first because it is the most important

[TahlilGaran] Dictionary of Contemporary English ▲

first things first
the most important thing should be thought about or done before any other.
You may need to get a better Internet service, but first things first — see if the one you have can do what you want.

[TahlilGaran] English Idioms Dictionary ▲

First things first.
something that you say in order to tell someone that more important things should be done before less important things.
I know you want to talk about my trip, but first things first, how have you been while I was away?

[TahlilGaran] English Idioms Dictionary ▲

first things first
the most important things must be taken care of first
We did first things first and cleaned the kitchen before cleaning the living room.

[TahlilGaran] English Idioms Dictionary ▲

first things first
Other things must wait until the most important and necessary things are done.
Study your lessons before you go out to play. First things first.

[TahlilGaran] English Idioms Dictionary ▲