Really depends on the breeding and when they are born what time they are ready to go.
You wouldn't need to shear lambs but you would almost certainly need to dag at least some of them. As for foot trimming, that isn't predictable although by choosing a breed or cross with good feet you can certainly cut down on foot care. Don't forget you will also probably need to worm and depending on where you are fluke them at the very least.
Worth its weight in gold just to see what you are letting yourself in for and then to help if you decide to go ahead is Tim Tyne's Sheep Book for Smallholders. But sadly there is no real way to ensure you won't have to at least trim some wool and some feet. Sheep can be high maintenance although again some breeds are much higher maintenance than others and your local conditions also contribute to how much work is needed.