Being that it's your first rc you likely wont have any other motors lying around.
in that case a trip back to the hobby store and hope they can trouble shoot it for you.

did your throttle trim setting dial move on the radio?
Is it the SC-15 speed control?

Give us more info. Receiver/radio models and speed control model.

Just found this and have no idea but it may help.
Don't know where you guys are getting your info - the SC15 ESC *is* programmable.

For the first ~2s of EVERY poweron it goes into programming mode = the LED blinks green & red.

Move your trigger Full Fwd then Full Brake within this time and it will memorise those settings
then makes a soft chime; the motor will not run during the programming.


It does it EVERY poweron, so be careful if your TX is being held by anyone fingering the trigger inadvertently.
Only if the throttle remains @ neutral for the 1st 2s then it'll just reuse its last-set programming settings.