RTL + Right-align in text boxes
⌃⌥⌘→ (control-option-command-right) makes the selection left to right
⌃⌥⌘← (control-option-command-left) makes the selection right to left
⌃⌘→ (control-command-right) makes the paragraph left to right
⌃⌘← (control-command-left) makes the paragraph right to left

If you didn't choose a right-to-left input source as the default input source when you created your account, you might have to enable the shortcuts from System Preferences: