If you want to do it in reality, you'd better hold an exhibition first. Of course, this requires rich contacts and good places. If your father has many friends, you can send invitations. If you are famous enough to join, you can also hold a press conference to announce that you will hold this exhibition (it won't cost much to find media). What's the effect of watching the exhibition? If the joining effect is good, it can be auctioned on the spot. Of course, the premise of these is that your father's works are valuable.
If it is done online, I don't quite agree.
One: in your question, you can't make a web page. It takes a while to study, and it costs a certain amount to find someone to make it. Although it costs money to hold an exhibition, even if the exhibition doesn't sell works, it can hurt your father's reputation.
Two: You should consider how to sell it online. Calligraphy is different from other things. If you want to send it, it is difficult to keep it clean, leaving no traces, humidity and other problems.
Three: the effect is difficult to guarantee. After all, online sales are not as effective as direct exhibitions. Besides, how will your website be published after it is made? Also, I believe that most people who buy calligraphy works should not always surf the Internet.
The above is just my personal opinion. If you have any questions about .........., please ask Han Hai.