MSP430 (FR5969) What time is it?

I'm fairly new not just to MSP430 but to micro controllers in general. I was surprised that a clock was just included in most micro controllers. So, I learned about RTCs and I've had great success connecting these via I2C to my lightblue bean 3.3V, Arduino Uno, Trinket and spark core.

But, I can't get it to work on MSP430FR5969. I'm using breakout boards. I have read some forum posts that mention I2C "needs pull ups" what are pull ups? Are there resistor pullups in these ( DS1307 Real Time Clock breakout board kit , Mini RTC module for Raspberry Pi and Arduino) breakout boards?

Would I be better off buying a DS1307 chip and making my own board? Are there any schematics for this?

My understanding is pullups are needed sing MSP430 is 3.3v, but so is the  lightblue bean 3.3V and trinket and spark core. What is the difference?