We have a similar set up to you 5 acres, divided up into paddocks for horses, we have bought lambs in 2 years in a row, so are not experts but it might give you an idea.
We bought 4 lambs in the first year, day old and bottle fed, we bought them in April and they went to slaughter in October, we did not worm as they were on new ground that year, we also did not shear although we did clip round the tail area to keep clean, feet were fine no problems, bought them in a couple of days before they went to clean them up, they had no shelter when they were older, however the weather was fairly good.
Second year we decided to have 6!! day old bottle fed again, mistake! There are 3 of us here but it meant that we all had to get up every day and go to bed late at night, would stick to 4 next time, again they were bought in April and went in October, again they had no shelter when they were older, had a foot problem with one of them, nasty puss, but daughter (who loves that kind of things) cleaned it all out and looked after it, no more problems after that.
Ours were tagged and docked before they left thier place of birth and under 1 year they only need the one tag
What we have learnt from those experiences: Buy in April, slaughter in October, get booked in before the Christmas rush and the weather turns, if we bought day old again would only have 4, if we bought them weaned would have more, probably 6. We had a mixture of girls and boys, works fine because they go before they get too interested in each other!! Not sure if we were just lucky but they have been relitivly trouble free both years.
Would love to have a small flock all year but hubby is reluctant to keep them over winter
Hope that is of some help