Ball handling help

I’m an 18 y/o 6’4 215 player who always played center in high school (as anyone over 6’0 usually would) but I’m playing in a small league and have been the one taking the ball up the court. I like playing this pg/big man play style but I turn the ball over too much because I’m not used to handling the ball so much. I’m left handed.. not sure if that matters. If anyone can help me by giving me advice. I’m not looking for drills because I can find those all over YouTube. I’m asking for any tips on how to secure the ball more esp when driving. Like when to keep the ball low vs high.