The first boss who took a chance on a kid with no experience did you a real favor. Make them glad they did.

Hiring somebody with no experience means accepting a risk that cannot be settled in advance. Whoever gave you your first job decided you were probably worth the trouble of training, against the easier option of someone who already knew how. That was a bet placed on very little information. The only thing that settles it is what you do afterwards.

Be reliable at the job you have in a way that makes the bet look sensible. Turn up early, learn the dull parts, stop needing to be chased. Later you will know exactly where your first reference came from.