I know some people like to shear lambs but it's breed dependent and generally they don't need it until they reach a year. If the breeder says yearly I'd go with that. It's not super hard to learn how to take wool off, but it takes some practice and the equipment can be expensive. I always offer to show people and after watching me they always decide to just hire me to come back. If you have someone local that does a good job it can make more sense financially and in terms of time/effort to just hire someone to do it. There are plenty of pros out there who will cut your sheep to ribbons though so make sure to ask around to find a good one.