Jeffrey, I’m using a slightly modified and customized version of the TwentySixteen standard theme. WordPress supports microformats v1 in core, so most themes will do somewhat well. If you’re looking for the most IndieWeb friendly themes, take a look at some of the ones I and others have documented at https://indieweb.org/WordPress/Themes#Themes_Supporting_Microformats. Let me know if you have any other questions. You might also try asking for help in https://chat.indieweb.org/wordpress/.