From where to start

I am a novice level player who have not seriously studied how to play chess.

Recently, I find myself very weak in opening. 

However, some people say that I should first study endgame. From where do I have to start?

Thanks.

Do a little bit of everything:

Analyze your games for blunders/mistakes,

Study the openings that you played in your games with an opening explorer/database to see what top GMs played in those openings.

Do some tactics

Do some more tactics

Get a coach if you have enough money 

Study common endgames

Play, to reinforce what you've learned

Thank you so much, Boogalicious!

My question seems a little bit silly haha.

"Do a little bit of everything" makes sense!

Thanks :)

Not silly at all. I started a year ago. I used a book with lessons and exercises (Idiots guide to chess). It starts with how to checkmate with different pieces, then tactics, then openings, and then strategic ideas. As a beginner don't try to memorize all kinds of openings. That's no use.