There are lots of options and keyboard shortcuts in atom. You don't need to learn them all, but the ones below will help you be more efficient. There's also a flight manual if you want to read more about atom.
|keys| result|
|------|------|
| PageUp | move up a page |
| PageDown | move down a page |
| Ctrl-g | enter line number, move to that line |
| Cmd-Left or Ctrl-a | move to beginning of line |
| Cmd-Right or Ctrl-e| move to end of line |
| Ctrl-RightArrow | move right one word|
| Ctrl-LeftArrow | move left one word|
|keys| result|
|------|------|
| Ctrl-l | select line (repeat to select multiple lines)
| Ctrl-Ins | copy line
| Shift-Del| delete line
| Shift-Ins| paste line
| Ctrl-] | indent line
| Ctrl-[ | unindent line
|keys| result|
|------|------|
| Ctrl-z |undo
| Ctrl-Shift-z |redo
| Ctrl-o |open file
| Ctrl-n |new file
| Ctrl-s |save
| Ctrl-q |quit
|keys| result|
|------|------|
| Ctrl-Shift-= |increase font size
| Ctrl-Shift-- |decrease font size
| Ctrl-TAB |go to next Tab
| F11 |toggle full screen