Just got my first Rowerg. .. a bit overwhelmed

I just bought my first rowerg (based of recommendation alone never tried a rower) since I needed a low impact cardio.

Now I'm overwhelmed by how to get the correct form etc. I'm feeling the majority of ache in my arm so I'm not sure if I'm doing it wrong.

basically I'm extending my arm lean forward a little then kick with my legs arms fully extended back straight. When legs straight i pull when lean my back a little. Then reset. Relax and go back to the beginning

I'm getting around 750 cal/hr on the pm5. Resistance at 4-5 around 123 drag factor.

Sorry for the long post. Just want to get some help here please. My goals - 30mins to 1hr per day cardio get healthy.