Hi,
one power supply unit with min 3A should be enough to start.
TEBA0841 is very simple and has no power connector. It's simple board to get access to IO, MGT loopback and one SFP.
You must connect 3.3V to one of the 3.3V power pins. I would recommend to use laboratory power supply with this carrier. You will source the module directly and with TEBA0841 there is no power protection circuit on the carrier.
In case you use MGTs, you must also add heat sink otherwise board will be come hot very fast!
Power consumption depends mainly on your design and cooling solution. Xilinx provide power estimator:
You should check XADC over Vivado HW manager from time to time to check temperature. Xilinx specified junction temperature on the data sheet:
XADC temp should be below this temperature. Commercial <85°C and in case of industrial <100°C if you come over the limit, current will be rise very fast and FPGA can be damaged.
br
John