Will this bolt straight onto my van without any modification?

Yes. This assembly uses factory mounting points — no drilling, cutting, or bracket work needed. The connector matches your existing wiring harness.

Do I need to replace the right side headlight too?

Not required. You can swap just the left side. If both headlights are dim or damaged, replacing both ensures even light output and appearance, but this assembly is sold individually.

Is the bulb included?

Bulb is not included. You'll transfer your existing bulb from the old housing or source a replacement separately.