See /Users/luowanqian/local/texlive/2019/index.html for links to documentation. The TeX Live web site (https://tug.org/texlive/) contains any updates and corrections. TeX Live is a joint project of the TeX user groups around the world; please consider supporting it by joining the group best for you. The list of groups is available on the web at https://tug.org/usergroups.html.
Add /Users/luowanqian/local/texlive/2019/texmf-dist/doc/man to MANPATH. Add /Users/luowanqian/local/texlive/2019/texmf-dist/doc/info to INFOPATH. Most importantly, add /Users/luowanqian/local/texlive/2019/bin/x86_64-darwinlegacy to your PATH for current and future sessions.