Welcome!
I would recommend three sources to increase your understanding of
pf(8):
Although
pf(8) has stabilized over the last few releases of OpenBSD,
pf(8) has undergone radical changes over the years. If you have cobbled together the above rule set from information found on the Internet, you may be basing work on outdated material. When it comes to OpenBSD, staying with officially sanctioned information is
always the best strategy.