It supposes when I press 1,3,7 the view will change automatically to top, side or bottom, but somehow it doesn't work. And then I find non of my numpad work. I'm using 2.8 by the way.
The number pad hot keys still work in 2.8. Have you remembered to re-apply emulate numpad in system preferences, because it is a new version of blender so the settings will be set to default (I made that mistake myself :) Also you can use the button next to the 1 to switch through lots of different views in 2.8. I think that may have been mentioned in the above answers. Hope I could have been of some help!
nope. New shortcuts on 2.8, so forget about the 2.79 shortcuts. Though, if you want there´s a choice for 2.79 button config RIGHT on the FIRST install FIRST run of Blender to pick your right or left click select and your button configuration. On a 3D VIEWPORT hold ALT+Drag the MIDDLE mouse UP (it will take you top view), do the same combinations with left, down, right for each viewport.
Thanks for voting my answer.