Hi @Omicove.
I am afraid that there is no way to disable sleep mode entirely, but as @snake218 mentioned you are able to alter the inactivity time frame for when the display is going into sleep mode. This is done by going to Settings > Display > Sleep.
There is also an option enabling you to double-tap on the screen while in sleep mode to wake the display and see the lock screen. To find this option, find and tap Settings > System > Gestures > Tap to show lock screen.
I hope that answered your question!
