EFM8 Sleepy Bee USB connection
I would like to connect USB for programing etc. and I assume I connect the Data+ to pin 7(P2.7 / C2D) and Data- to pin 6(RSTb / C2CK). Is this correct?


No. That MCU doesn't support a USB connection, so that won't work.

Since you mention programming, the manufacturer shows the programming options here. That MCU uses the Silicon Labs C2 debug &amp; programming interface - ignore mentions of JTAG or SWD on that page, as they apply to other MCUs from that manufacturer.