Hi I'm kinda new to the game and was wondering is there a way to get the game to run in full screen cuz im getting black borders guess it got something to do with aspect ratio?

This game is the most resizeable app I've seen, just switch all freeform windows options at the bottom of developer options, or allow app to be displayed in fullscreen, somewhere in permissions - it depends on the phone.
It's also may be called hide/show notch, which is different for everey UI, and placed somewhere else in settings.
Also try to switch phone into gestures mode (swipes), which removes three bottom buttons, so all apps become as fullscreen displayed.