Mini pc help

Hi so I brought a mini pc and a monitor both brand new like a week ago so I could play the sims and have all the cute cc and what not. I'm not able to play through most time the computer shuts down before I  can start the game. Then if it does work for a bit it just randomly shuts off.. I've did some research online and it's saying either my power source isn't good or my computer is running hot and overheating.. Does anyone have a similar problem or know what I can do to fix it. Please help I just want to be cute and play my game.

Monitor is xgaming brand ...Pc Is soyo brand 16gb and 500ish gb..

Thank you