Start with the purpose
A shop, garage, equipment cover, business workspace, and storage building may all share similar dimensions while needing very different layouts. The intended use is usually the quickest way to sharpen the conversation.
Think about what needs to happen inside the building every day. Vehicles, tools, roll-up doors, insulation, clearance, and workflow all come from that answer.
Know the rough footprint
Rough dimensions are enough. If the building might land at 30x40 or 40x60, that is still useful.
If there is a slab involved, note whether it already exists, is still needed, or should be discussed as part of the same quote.
Bring the site notes you already have
A simple note about slope, drainage, access, or pad prep can save time early. These are the things that often separate a broad price guess from a more grounded next step.