I recently finished training camp for for the first time and one of my players was in a message that said he gained 14 points but I saw no change in his overall rating. So what does that message mean?

It means he gained 14 total points across multiple skills. For example, an offensive lineman gains 1 in Strength, 4 in Pass Blocking, 4 in Run Blocking, 2 in Hands, and 3 in Endurance which is 14 points total.

Many thanks!!