Not sure whether it is feasible for you, but before we brought our own sheep, we baby-sat some sheep for a neighbour. We had 10 of them for 3 months, and it gave us chance to see how we could handle them, how our fencing was, and give an idea about if we could cope - in all aspects - before taking the plunge. Neighbour came to do daily checks for the first week ( we walked round with him ) and then weekly after, unless we were worried about something. He showed me how to check for weight/condition, eyes, feet , signs of diarrhoea, pink gums etc and while they were here he wormed them once ( I helped, and got to practice ) and I went to his place to do injections, foot care and shearing. I sprayed them for summer flies, and got an idea of who was laying down for cudding/chewing and who looked tucked up, and who was first for feeding, and who was shy. Learning the basics of looking at each one and checking they are walking fine, have clean eyes, no dribbling, and no messy backsides was invaluable. It was a great introduction, before I got my first 4, and combined with the Tim Tyne book, internet, and vet advice, has been a good starter.
Good luck with your first sheep