You're probably best to see someone else hand shearing before you have a go. They can show you how to recognise the rise, and judge when it's high enough from the skin. There are good and bad ways of holding the shears, and a special way to hold and turn the sheep to keep the skin taught. Remember never to pull the wool as it causes the skin to tent and makes a big cut likely.
There are some clips on youtube, some of which, but not all, are good.
Mr F started by doing a Wool Board machine shearing course, then when he'd got the hang of that he adapted the method to hand shearing. Having watched him shear loads of sheep, I have done some myself, mostly when they have a good rise, but now I find the contortions you have to go through a bit awkward. He's quicker than me anyway. It does take many sheep before you are confident of remembering the technique and order of shearing - not something you can learn just watching once.
Of course, with just a few self shedding sheep, you can roo them, and this is probably the best way for you. No contortions, just sit on a milking stool in the sun, communing with your sheep