how to beat opponent in head up

i lose every head up that sad

HU requires skills and strategies different from multi player formats. The first thing to do is understand preflop strategy. The free version of GTO WIZARD is good for that. In the study MTT section you can look at HU ranges to get a strong idea of how to play your hands preflop.
You can also solve 1 post flop spot everyday or 7 spots a week which is very good for a beginner to learn HU play.
You will learn bet sizing -bet frequency and value and bluff hands that play the same way.

Reach out with questions if you want.

I think you need play more aggressive