TopolearnA good prompt shows where you are, which branch you are on and whether the last command failed.
The prompt is the PROMPT variable (alias PS1); RPROMPT is shown on the right and disappears as you type into it. Zsh expands percent escapes in them:
%nuser,%mshort host name,%~current directory with~for home,%1~only its last component,%#shows#for root and%otherwise,%?the last exit status,%Tthe time,%F{red}...%fforeground colour (names or 0-255),%B...%bbold,%(?.yes.no)a conditional: here "yes" if the last command succeeded.
To include the output of variables or functions that change, set PROMPT_SUBST and write the prompt in single quotes, so ${...} is expanded every time the prompt is drawn rather than once when .zshrc runs.
For the git branch, zsh ships vcs_info: load it, call vcs_info from the precmd hook (run before each prompt), and use $vcs_info_msg_0_. Its formats style uses %b for the branch; it can also show staged or unstaged changes.
print -P '...' expands prompt escapes so you can experiment. If you prefer a ready-made prompt, Powerlevel10k and the cross-shell Starship are popular, but understanding the escapes lets you read and tweak them.
Example
autoload -Uz vcs_info
precmd() { vcs_info } # refresh before each prompt
zstyle ':vcs_info:git:*' formats ' (%b)' # %b = branch name
setopt PROMPT_SUBST
PROMPT='%F{cyan}%n@%m%f %F{yellow}%~%f${vcs_info_msg_0_} %(?.%F{green}.%F{red})%#%f '
RPROMPT='%F{240}%T%f' # time on the right
print -P '%F{yellow}%~%f' # try escapes: ~/projects/app
print -P 'last: %(?.ok.failed with %?)' # last: ok
# The result looks like:
# ada@laptop ~/projects/app (main) % 12:41Remember
- %n %m %~ %# %? are the core prompt escapes
- %F{color}...%f for colour, %(?.ok.fail) for conditionals
- PROMPT_SUBST plus single quotes for values that change, vcs_info for git
Watch out for
- Writing PROMPT in double quotes with ${...}, so the value is frozen when .zshrc runs.