Will this bolt straight onto my truck without modification?

Yes—it mounts at factory rocker points. No drilling, no adapter brackets needed. Plug in the connector and you're done.

Does this come with a bulb?

The assembly itself is included; confirm your specific bulb type (H13 or HID) with your owner's manual or service tech before ordering, as that may be sold separately.

Can I buy just the right side, or do I need to replace both?

You can buy a single right-side unit. Many drivers replace one at a time—just make sure your left side is in good working order so beam spread stays even across the road.