Help for WG

I'll be moving to Germany in October and want to arrange a WG room in advance, like a month before. Is it possible to reserve a place remotely by paying the Kaution or signing an agreement before arrival? I am talking specifically about WGs that are free October on, but if it's possible I can give earlier ones a shot too.

Has anyone done this, or is it generally expected to move in more or less immediately?

Also, since I’ll be handling this online, what should I be aware of to avoid scams or shady setups? Any red flags or common traps to look out for?

Thanks in advance!