Your business card should have 3 main things:
Your branding in this case ( In the example Missevilkitty’s logo ) and the link to your site and how people can get a hold of you in this case an email address. I don’t always recommend adding your phone number because if you make say jewelry and you make custom items theres a good chance people will call you for a few things:
#1 To complain your not answering your DM, convos ( if your on etsy) or your messages on your FB page.
#2 to ask questions how you make the thing you sell.
#3 Call at random times. Do you want calls at 3am?