The first move I always teach in Aerial Hoop class, after explaining what is the correct way to grab the hoop, is called the Delilah.
The mechanics of doing this move is:
1) Grab the hoop with both palms facing each other on the hoop and, of course, lock your fingers.
2) Take a step under the hoop with one leg.
3) Place the other leg on the hoop so that the back of your knee will be on the hoop and point your toes.
4) Keep the hand opposite to the leg on the hoop while the other hand lets go.
To come down:
1) Place the free hand back on the hoop
2) Unhook the leg from the hoop to come down.
It's always important to train both sides, so once you are finished with one side try to do the other side. You will always feel that one side is better / more flexible / less painful than the other, but that's normal and it is very important to work on both sides, to make them both strong for your spine and muscles health.
As you can see I am wearing a back warmer when i'm training to keep my muscles warm while arching my back and working up.