It's not possible to open folder with one click in default "Icons" view in Finder. However switching to "Columns" view (`<Cmd>+3`) will allow you to open folder with one click.

Also it could be faster to just use hotkeys instead of trackpad/mouse. Use arrows to navigate inside "Icons" view, `<Cmd>+<Arrow Down>` to open selected folder and `<Enter>` to rename selected file or folder. When no file or folder is selected, you could just type in file/folder name and Finder will select closest match for you.