My iphone 4 screen flickering on lock screen when i press lock button or home button..appreciate any help..please iPhone 4

My iphone 4screen flickering on lock screen when i press lock button or home button..appreciate any help..plssss

iPhone 4.... Is it normal? It's not every time but lak once every couple hours I say... It also freezes every lak few day in an app? Not necessarily a downloaded one..... And then freeze and reboot? Is an iphone normal to do this time to time? Its about 3weeks old... Never dropped, never got wet... Just wondering is this a common thing that phones have? Wee glitches. Or am I worrying over nothing?