Do I need fasteners or brackets to install this?

This box mounts at factory points, but specific hardware requirements aren't confirmed — you may need to source fasteners depending on your bed configuration. Test-fit first before committing to any permanent installation method.

Can I get one for the driver side too?

This is a passenger side unit. Check if a driver side version is available separately, or contact support to confirm compatibility with a matched pair.

Will this interfere with a tonneau cover or bed cover?

Wheel well boxes sit inside the bed perimeter and shouldn't conflict with most tonneau covers, but clearance depends on your cover style. Measure before ordering if you're running a low-profile cover.