Fred,
As far as official competition (at least in Canada--we are following AIDA rules), you've got a 1.5m starting area, marked off by a rope strung across the pool lane. So that means you can stand up and make a surface dive from that position, push off from the wall--as long as you get under the rope.
As for the turn, you have to touch the wall with your hands or feet, but you must touch it. Personally, with the monofin, I glide to the wall, touch it with my hand, push off and spin my body around on a horizontal axis quite slowly. Others do a swimming flip-turn.
Your spotter is supposed to follow you on the surface with a kick board ready to hand to you in case you stop your dynamic in deep water and need some support. It's not a disqualification to grab the kick board and hang on while you catch your breath.
Most people do dynamics along a pool edge and come up sideways so that their first motion is to set their elbows on the pool lip for firm support while they recover.
Hope that helps.
Pete