How long do steel drawings take?
For a domestic job - a beam or a goalpost frame - once the engineer's calcs are in hand, a few working days is typical for setting-out and fabrication drawings.
Larger frames (portal, mezzanine, agricultural) take longer and usually go GA-first for approval, then fabrication drawings.
The clock really starts when the calcs and architect drawings are available - I can't detail ahead of the engineer's design.
Structural sizing, spans and load calculations must be carried out by a qualified structural engineer. These pages help you plan the drawings you need - they are information only and are not structural engineering advice.