Every command has a name, and you can do M-x and type in that name, with tab completion, if you forget the keyboard shortcut. Even better, you can enable ido-mo

Every command has a name, and you can do M-x and type in that name, with tab completion, if you forget the keyboard shortcut. Even better, you can enable ido-mode and install ido-vertical-mode, and see a list of possible command completions without pressing tab. I also highly recommend remapping your caps lock key to control.