If you want to know where every pin goes on this board then you should look at the schematic in the User's Guide. But more importantly, you should get familiar with the datasheet for the microcontroller on the board.
You don't see P1.0 and P1.1 because those pins are not brought out to the booster pack headers (connectors). Those pins are used within the launchpad board for something else. (They are not even UART pins as you hoped.)
P3.3 and P3.4 is the only UART connection that you have available through the booster pack headers. The other UART is on P4.4 and P4.5 and those pins aren't brought out through the headers. So you should probably try to get P3.3 and P3.4 working. Did you download TI's example software for this launchpad? There is probably an example program that uses the UART.
P3.3 and P3.4 are multiplexed as are many GPIO pins on typical microcontrollers. These particular pins can be configured as GPIO, a UART, or an SPI port. SOMI and SIMO are abbreviations related to the SPI function. Your code will have to configure these pins for the UART function. Read the datasheet and study the example software to learn how to do this.
I'm not sure where you saw four UARTs. The microcontroller on this particular launchpad has four serial interfaces but only two of those interfaces are designed for UARTs. The other two serial interfaces can be SPI or I2C.