You only need the one from the drivers side near the alternator. It plugs into the loom that goes down to the alternator. Yes it has fuses in it that you dont need like lights etc.

A main power feed goes into this fuse box to run the car.

I have removed the fusable links and used a 100amp circuit breaker instead on the feed to this fuse box. But you could re-use the fusable links. Some cars have a 100amp main fuse at the battery terminal. Which is a option if the battery is up front.