Most home bar builds fail because they start with the wrong question. People ask what size the bar should be. The right question is where people will stand. A bar is not a piece of furniture. It is a room divider, a gathering point, and a workstation that happens to have a countertop and some shelves behind it.
A comfortable standing bar height is 42 inches from finished floor to the top of the bar surface. Bar top depth should be 16 to 18 inches minimum. Behind the bar, leave 36 inches of clear working space. Run electrical before closing the walls: two dedicated 20-amp circuits at minimum. A bar sink is not required but dramatically increases how often you actually use the bar.
Pendant lights at 30 to 34 inches above the bar top provide direct task illumination without getting in the sightline. Backbar shelving with LED strip lighting on the underside of each shelf, warm white, 2700K to 3000K. Wire the strips to a dimmer. A bar at full brightness is a hardware store. A bar at 40% brightness is a destination.