By default you will be in EDIT mode. This is the vim-like mode for entering commands and moving around in the editor. Press i to enter INSERT mode. In EDIT mode, press v to enter VISUAL mode and V to enter VISUAL-LINE mode. To go back into EDIT mode press ctrl-c or ESC. Read more about specific keybinds for each mode with :help.
When in EDIT mode, press : to open the command dialog. Type a command and press enter to run it, or escape to cancel.
Create a new file with ctrl-n or :n [filepath]. Use ctrl-o (and/or space-o when in EDIT mode) to open the file explorer. Navigate with vim keys or arrows. To open a file by path use the :o [filepath] command.
Create a new tab with ctrl-t. Switch between tabs with ctrl-e. Navigate the menu with j/k or arrows and select with space/enter. Close a tab with ctrl-w.
Enable split buffers with ctrl-y, and unsplit the same way. Navigate to the left and right buffer with ctrl-h and ctrl-l.
Press ctrl-f to find a string in the buffer. The results are incrementally highlighted. Press enter to go to the first result. Use n and N to navigate to next and previous result.