I don’t understand accuracy

Don't worry about getting banned if you aren't cheating or violating any other Fair Play rules.
With that being said, Accuracy is a measure of how good your overall moves were compared to what the engine thought was best. Even if you make mistakes and inaccuracies, playing good or decent moves throughout the rest of the game will increase your Accuracy. In your example, the game lasted 50 moves which gives plenty of moves where you could have your Accuracy bounce up. The last 10 moves in your game are pretty straightforward for finding good moves for example, so it is likely you also got plenty of Accuracy from that portion alone.

Chess.com does NOT use the accuracy stat for cheat detection.
If you aren't cheating, don't worry about it.

Chess.com does NOT use the accuracy stat for cheat detection.
If you aren't cheating, don't worry about it.
+1

CAPS (accuracy) is better explained by IM @DanielRensch here than I could type out quickly, so here
p.s. As states already, chess.com cheat detection is much more advanced than CAPS score and that statistic is not a factor in determining Fair Play violations