You have NOTHING to worry about as far as physical appearance goes. It will take a little time for You to really own that - but eventually You won't even give it a second thought...and TRULY You don't have to.
Confidence too comes with time.
Just be Yourself, let go of fears and expectations and they will all come to You anyway!!!
As far as Gaydar goes...it can be very subtle. A look dead in the eye that lasts a second longer than usual. A handshake that is slightly more firm than expected with just an extra moment of contact. If coupled with the aforementioned lingering eye contact -- Yer in ( so to speak). If his attention is focused on You even in a group and he seems more interested in Your input than everyone else's, Yer good.
Of course if He buys dinner, gives You a Philippe Patek and insists on making You breakfast the morning after - it's almost a dead give away...
Just be the best You can be and everyone else will want to know You!!!