You should probably calibrate the ESC. There are many great videos explaining it, but it essentially tells the plane what 0 and 100 throttle is. Just remember, take off the prop if you don't want to risk ending up with A cut, or worse. Turn on the radio first, then bring the throttle stick to 100 (no trim). Theb plug in the battery and the motor should start beeping. eventually (if you think it is done, wait 15 more seconds just in case) bring thr throttle to zero, let it beep some more, and the you should be done 😁